Monthly Archives: February 2017

Taken together numerous studies highlight that changes in population size

Taken together, numerous studies highlight that changes in population size induced by host-parasite interactions can have a strong effect on genetic diversity, drift and selection, and, thus, are likely to shape eco-evolutionary feedback. As a consequence, coevolutionary dynamics are not identical under changing and constant population size, potentially making the latter an inaccurate approximation of the natural situation.
5. Future directions in studying host-parasite coevolution
The exact traits, the involved genes, and the underlying selection dynamics represent central topics of particular current interest for our understanding of host-parasite coevolution. Future research at both the theoretical and the empirical/experimental level should address these topics in consideration of temporal variations in population size. It would be of particular value to assess to what extent different types of parasites (e.g., micro- versus macro-parasites) vary in their effects on host population dynamics, as these usually have different population sizes themselves and may thus differ in their ability to respond to an adapting host.
So far, an enormous wealth of theoretical work has been produced on host-parasite coevolution. Several models allow for interaction-induced changes in population size, even though most of these models do not specifically assess their effect on the coevolutionary dynamics. The available models are based on different approaches, including game theory and adaptive dynamics (Lenski and May, 1994, van Baalen, 1998, Dieckmann, 2002, Gandon et al., 2002, Restif and Koella, 2003, Best et al., 2009, Best et al., 2010 and Boots et al., 2014), or they explicitly define the genetic basis of the interaction (e.g., matching protein kinase inhibitor or gene-for-gene interaction types) (Frank, 1991, Frank, 1993, Gandon et al., 1996, Hochberg and Moller, 2001, Day and Gandon, 2007, Gandon and Day, 2009, Gokhale et al., 2013, Ashby and Gupta, 2014 and Song et al., 2015). Different approaches all come with specific advantages for characterizing host-parasite coevolutionary dynamics; however, genetically explicit models are particularly useful because they can capture non-equilibrium population dynamics and thus allow a more straightforward comparison with empirical data (Day and Gandon, 2007 and Gandon and Day, 2009). A particular challenge for the future is to assess the relative influence of both interaction-induced population dynamics across time and the resulting stochastic effects on the process of co-adaptation. Such an assessment requires that results are compared from models with and without interaction-induced population size changes and also with and without stochastic processes, especially genetic drift (Parsons et al., 2010 and Black and McKane, 2012). To date, such comparisons have only rarely been undertaken. In fact, only few modelling approaches simultaneously take into account both changing population size and stochasticity (Dieckmann and Law, 1996, Dieckmann, 2002, Quigley et al., 2012 and Gokhale et al., 2013). One of these studies indeed identified a dramatic effect of these two factors on coevolutionary dynamics (Gokhale et al., 2013). In particular, the combination of stochasticity and changing population size can enhance fast allele fixation (consistent with RSS dynamics), while the same model with constant population size or the deterministic version produces the pattern typical for NFDS. In the former case, the fixation events coincide with antagonist-mediated selection during a population bottleneck, suggesting strong interactions between selection and population size variation (Gokhale et al., 2013). These approaches clearly need to be extended to allow for more complex genetic interaction patterns and/or more realistic population structures.
Similarly, to date there is also only very little empirical data which directly tests the influence of interaction-induced population size changes on the coevolutionary process. Ideally, population dynamics should be recorded along with temporal evolutionary or genetic characteristics of the studied populations (Duncan and Little, 2007, Gsell et al., 2013 and Auld et al., 2014). Changes in parasite abundance are particularly difficult to measure. Fortunately, novel approaches, such as phylodynamics and skyline plots (Biek et al., 2007, Pybus and Rambaut, 2009 and Ho and Shapiro, 2011) can be used to reconstruct population history based on genetic information. Another interesting technique is a combination of sequence ‘barcoding’; and deep sequencing which has been used to infer the founding population size of Vibrio cholerae during the onset of infection ( Abel et al., 2015). In fact, the recent advances in NGS-genotyping, bar-coding and related techniques will facilitate the generation of longitudinal data from coevolving host and parasite populations, even though detecting signatures of coevolution from genome sequences is not a trivial task (Tellier et al., 2014; see also Croze et al., 2016). Although difficult to obtain, such type of data would help to elucidate the patterns of population dynamics in coevolving populations and, most importantly, evaluate its effect on evolution of traits and genetic diversity.

Hydrogen gas bubbles were visible until months after implantation

Hydrogen gas bubbles were visible until 12 months after SYN-117 cost (Figs. 3a, c and 4a–d), which produced little areas of cell displacement around the implant (Fig. 4e, g). The repopulation of these areas occurred mostly with adipocytes (Fig. 4e–j). Compared to the preexisting intramedullary matrix the local cell density in these regions was slightly lower, but the size of these areas shrank continuously after full pin degradation (Fig. 4i).
No pathological increase in inflammatory cells—such as leucocytes or plasma cells—in response to foreign objects was observed in histological stainings over the whole examination period (Fig. 4f, h, j).
3.3. Mg-distribution and Ca/P ratio
Fig. 5a–h illustrates the Mg mass fraction and Ca/P molar ratio in the mineralized cortical bone relative to the basal level of the respective bone. The LA-ICP-MS investigations were carried out adjacent to the pin upon degradation of the WZ21 implant. During the first months of pin degradation a significant increase in Mg was observed in the cortical bone up to approximately 2–3 mm from the pin boundary. An increase of the Mg mass fraction up to 50% from the basal level was measured (Fig. 5a, b).
LA-ICP-MS measurements after 1, 9, 15 and 24 months: The left-hand side shows the resulting chemical images: nearly all of the pin remained after 1 month (a); continual degradation of the pin after 9 and 15 months (c,e); full pin degradation at 24 months (g). The right-hand side (b,d,f,h) shows the Mg mass fraction (solid blue circles for upper cortical bone, open blue circles for lower cortical bone) and the Ca/P ratio (solid red squares for upper cortical bone, open red squares for lower cortical bone) relative to the basal level for the upper and lower cortical bone areas. Error bars represent standard deviations.
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The increasing dissolution of the implant generated significantly increased Mg concentrations in the cortical bone near the remaining implant parts from months 9 to 15. Increased Mg mass fractions of about one order of magnitude were observed in the lower cortical bone area of one example (month 15; Fig. 5e, f), where pin residuals were still present. In contrast, areas of fully degraded implant parts—where re-mineralization had already occurred—showed only slightly increased Mg levels (up to 20%) (Fig. 5c–f). After 24 months the Mg concentrations of undisturbed bone areas and in the area of newly formed bone at the former implant site overlap within the measurement uncertainties and show therefore no significant difference (Fig. 5g, h).
In the medullary bone area, no significant changes in the bone could be observed. Even though similar increased levels of Mg were observed close to the pin boundary, no significant Mg enrichment was detected in the newly formed bone area.
In contrast to high Mg concentrations measured in the area directly adjacent to the pin from the first months, the molar Ca/P ratio of this area did not significantly differ from the ratio of undisturbed (basal) hydroxyapatite (Fig. 5b). Between 9 and 15 months a steady decrease in the Ca/P ratio up to 20% was measured in the adjacent pin areas (Fig. 5d, f). After 24 months the Ca/P ratios showed no significant different molar ratios anymore throughout the whole cortical bone in correspondence to apatite in the cancellous bone (Fig. 5h). The cancellous bone material in the medullary area also showed no distinct variation in the Ca/P ratio throughout the whole degradation process.
3.4. Yttrium distribution
Fig. 6a–d depicts the Y mass fraction in the mineralized cortical bone directly adjacent to the pin relative to the basal level (which was about 100 ng g?1). Even after just one month (Fig. 6a) the degradation of the material resulted in an enrichment of Y in the boundary region adjacent to the implant. Even though the Y content was still low compared to that observed during the subsequent degradation process, high variations in Y distribution (regions of 10-fold differences in the concentration vs. regions with basal Y levels) were already observed (reflected by the error bars in Fig. 6a). After 9 months (Fig. 6b) the Y mass fraction in the cortical bone showed a distinct increase at the pin boundary, with pronounced variations in the Y mass fraction (reflected by the large error bars). This phenomenon became even more pronounced as the degradation process advanced. The Y concentration increased locally by almost three orders of magnitude compared to the basal level in the bone after 15 months (Fig. 6c), and the variation within up to 2 mm from the pin boundary was almost two orders of magnitude. The large variations can be interpreted as migration of metallic particles. However, after 24 months (Fig. 6d), when the pin was fully degraded, the Y concentration had reached nearly basal levels within the entire cortical bone area.

Three methods were used to estimate micronekton organisms cm biomass

Three methods were used to estimate micronekton (organisms 2-20 cm) bch cost and species composition: using an EK60 echosounder, net sampling and the S-ADCP (see Section
Acoustic data were collected continuously during the cruise using a EK60 echosounder (SIMRAD Kongsberg Maritime AS, Horten, Norway) with four hull-mounted split-beam transducers (38, 70, 120 and 200 kHz). Echosounder calibration was performed according to Foote et al. (1987) at the beginning of each cruise. Due to the presence of noise in echograms, linked to the specificities of the installation of the sounder on the R/V Alis and to rough seas during the cruises, the water column was only sampled down to depths of 100, 200, 250 and 600 m for the 200, 120, 70 and 38 kHz channels respectively. A data cleaning step was performed with Matlab? (MathWorks, Natick, Massachusetts, USA) filtering tools provided with the Movies3D software (IFREMER). The EK60 signal was analyzed in terms of scattering volume (Sv) (MacLennan et al., 2002). It was not possible to calculate micronekton biomass from echograms produced as the Sv to biomass conversion requires knowledge of the acoustic properties of the detected organisms added to a complex inversion of the signal and has not yet been performed for our dataset. The 38 kHz frequency is commonly used as a proxy for micronekton (Bertrand et al., 1999, Kloser et al., 2009 and McClatchie and Dunford, 2003) and was used to represent micronekton over 0-600 m.
To describe the spatial structure of the micronekton biomass derived from the 38 kHz EK60, we removed the day/night signal from the data as the strong diurnal vertical migration of micronekton might mask spatial patterns. The data were assigned to either day or night and average values were calculated for each period for each cruise. The daytime (resp. nighttime) mean was subtracted from the daytime (resp. nighttime) values to produce anomalies for each period.

It has been proposed that strontium

It has been proposed that strontium affects the differentiation pathway of bone stem purchase Purmorphamine through inhibition of sclerostin expression in vitro [68]. Surprisingly, it has been published that sclerostin, considered as a non-classical BMP antagonist and inhibitor of the Wnt signaling pathway, is induced in SaOS-2 cells via exposure to the osteoinductive cytokine BMP-2. Therefore, it was consequent to study the expression of sclerostin in SaOS-2 cells in response to the microparticles, “Sr-a-polyP-MP” and “Ca-a-polyP-MP”. Basically unexpected was the finding that, in contrast to the increased expression of ALP and BMP-2, “Sr-a-polyP-MP” caused a significant reduction of the steady-state expression of sclerostin if compared to “Ca-a-polyP-MP”.
In view of the published non-consistent in vitro studies on the expression of sclerostin and the correlated effect on mineralization on bone(-related) cells in response to strontium and “Sr-a-polyP-MP” it was advisable to perform in vivo studies with “Sr-a-polyP-MP”, using the PLGA/microsphere (PLGA/MS) packaging system. This formation had already been successfully used for bone implant studies [33] ; [45]. Again the critical-size-defect system in rats was applied [45]. The data showed that after a 8 wk or 12 wk regeneration period the microspheres were substantially dissolved and replaced by bone-collagen material. Those micro-CT data (8 wk and 12 wk regeneration period) were substantiated by indentation studies (8 wk as well as 12 wk) revealing that the tissue, formed within the initial defect and implanted with “Sr-a-polyP-MP” microspheres, displayed a substantially higher density compared to β-tricalcium phosphate control and to Ca-polyP, containing “Ca-a-polyP-MP” particles.
5. Conclusion
The data summarized here show that microparticles, formed from amorphous Sr-polyP elicit in SaOS-2 cells an increased expression of both ALP and BMP-2, while the steady-state expression of the presumed inhibitor of human bone formation and the suspected inhibitor of bone cell differentiation and mineralization, sclerostin, is only slightly affected by the “Sr-a-polyP-MP”. In the presented scheme ( Fig. 11) it is outlined that the low expression of sclerostin (SOST), a mediator and negative regulator of the Wnt pathway, acting via interference with the LRP5/6 co-receptor, remained unchanged. Even more, we observe an increase in mineralization of SaOS-2 cells in response to “Sr-a-polyP-MP”, very likely via the Wnt-LRP5/6 co-receptors pathway. In future studies it will be approached to clarify if the “Sr-a-polyP-MP” interaction with the LRP5/6 co-receptors under shielding them against sclerostin. The induced expression of BMP-2, already observed for polyP, is even boosted in vitro using the “Sr-a-polyP-MP” particles. Taken together, the in vitro as well as in vivo data presented here might qualify those particles for future application as implant material for bone defects in humans. Furthermore, the particles studied here are non-toxic and by far less expensive than the introduced anti-osteoporotic compound strontium ranelate.
In the scheme it is proposed that “Sr-a-polyP-MP” increases the differentiation …
In the scheme it is proposed that “Sr-a-polyP-MP” increases the differentiation and mineralization processes in bone/SaOS-2 cells via the Wnt/LRP5/6 pathway (left panel). Sclerostin, a proposed inhibitor of the Wnt pathway, acts via interference with the LRP5/6 co-receptor and is assumed to be internalized and degraded together with the LRP5/6 co-receptor (middle). The “Sr-a-polyP-MP” particles significantly upregulate the expression of BMP-2 and ALP (not shown) very likely via activation of the Runx2 transcription factor, and apparently do not interfere with the Wnt pathway and does not affect the expression of the SOST gene, encoding for sclerostin (right).
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1. Introduction
During implant integration toward a successful clinical outcome, surfaces of orthopaedic materials interact with host bone cells, triggering a chain of biological events where osteoclasts and osteoblasts are involved in the replacement of damaged bone by new bone [1].
Synthetic materials for bone replacement are widely tested for their osteoconduction and/or osteoinduction, with substrates hosting osteoblasts or osteoblastic cell lines scored as promising materials. But the replacement of bone substitutes with newly formed bone implies that the material is gradually removed to leave space for new bone tissue, and recent research has shed light on the close osteoclast/osteoblast cooperation for bone formation and remodeling. Osteoclasts have been shown to secrete products to promote osteoblast precursor recruitment and differentiation and thereby promote bone formation [2]. Therefore, understanding the nature of the interactions of the different biomaterials used as synthetic bone grafts and osteoclasts is of paramount importance.

To our knowledge it is difficult

To our knowledge, it is difficult to install remote sensing equipments with larger aperture on a single spacecraft. Thus, researchers found the way of using satellite formation to form a larger virtual observatory aperture. In 2005, Krieger et al. [7] discussed the capabilities of multistatic SAR satellite configurations for different applications like high Nilotinib cost DEM generation using multibaseline single-pass crosstrack interferometry, 3-D vegetation mapping and layover solution with spaceborne SAR tomography, high resolution wide swath SAR imaging with sparse satellite arrays, multibaseline velocity estimation of moving objects and scatterer fields, spatial and radiometric resolution enhancement in SAR images, and multistatic imaging for improved detection and classification. Furthermore, some major challenges like phase and time synchronisation, multistatic SAR processing, satellite orbit selection, and relative position sensing are also addressed. A year later, they [8] introduced various spaceborne bi- and multistatic SAR configurations, and their potential for different applications such as frequent monitoring, wide-swath imaging, scene classification, single pass cross-track interferometry and resolution enhancement is compared. Furthermore, some major challenges such as phase and time synchronisation, bi- and multistatic SAR processing, satellite orbit selection and relative position sensing were addressed again. In 2007, Krieger et al. [9] gave a detailed overview of the TanDEM-X mission concept which is an innovative spaceborne radar interferometer that is based on two TerraSAR-X radar satellites flying in close formation. In 2010, they [10] presented an overview of single-pass interferometric Synthetic Aperture Radar (SAR) missions employing two or more satellites flying in a close formation. Xue et al. [11] also presented an overview of the small satellite literature on earth observation and future developments were put forward in 2008. However, we could find that when the satellites fly in formation, each satellite\’s orbit is different and there exists natural relative motion between satellites. On the other hand, there is no connection of any kind between them, so nothing could provide effective support for the formation, which brings great difficulties to the formation configuration control [12] ; [13].
Space tether is booming rapidly in both theory and techniques. Therefore, many researchers figured out a solution for space remote observation mission using tethers, which is to maintain the formation configuration by adding connected tethers into the satellite formation. Tragesser et al. [14] investigated the dynamics of tethering several subsatellites together in a three dimensional configuration. To keep the system oriented toward Earth, the Likins-Pringle rigid body equilibria were used as a baseline design. A flexible lumped-mass model was used to assess the stability for the tethered system. Three parameters related to the formation size, masses and spin rate were varied in order to find designs that were stable. Kumar et al. [15] explored the feasibility of rotating formation flying of satellites using flexible tethers. The system they used was composed of three satellites connected through tethers and located at the vertices of a triangle-like configuration. Huang et al. [16] proposed a coupling dynamics model for the tethered space robot system based on the Hamilton principle and the linear assumption. Wang et al. [17] ; [18] proposed a coordinated control of tethered space robot using mobile tether attachment point during approaching phase and post-capture for capturing a target respectively. They [19] ; [20] also proposed the Maneuvering-Net Space Robot System (MNSRS), which can capture and remove the space debris dexterously and mainly focused on coupled dynamics modeling and configuration control problems. In 2008, Vogel [21] assessed the utility of tethered satellite formations for the space-based remote sensing mission. Williams [22] considered a three-spacecraft tethered formation spinning nominally in a plane inclined to the orbital plane and obtained periodic solutions for the system via direct transcription that uses tether reeling to augment the system dynamics to ensure periodicity is maintained. Mori [23] proposed a tethered satellite cluster system, which consisted of a cluster of satellites connected by tethers and which can maintain and change formation via active control of tether tension and length to save thruster fuel and improve control accuracy. By now, most of the papers about multi-tethered system focus on the dynamics modeling and analysis. Hussein [24] studied the stability and control of relative equilibria for the spinning three-craft Coulomb tether problem. This paper mainly focuses on symmetric Coulomb-tether systems, where all three craft have the same mass and nominal charge values.

In most instances the ESS Processor

In most instances the ESS Processor Unit forms a direct chain with other Orbiter and Lander Subsystems: the nominal ESS side can only work with: the nominal Tx/Rx unit; with the nominal Remote Terminal Unit (RTU) of Rosetta’s On Board Data Handling (OBDH) system, etc.
The description of the redundancy management of the Lander Thermal Control Subsystem (LTCS) is beyond the scope of this paper – the ESS simply routes the associated power lines to the LTCS. Refer to Fig. 2 for a schematic of the Redundancy Concept of the ESS Processor Unit.
The Lander MSS and ESS redundancy concept.
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3.3. Detailed functional block diagram
A detailed functional block diagram of the ESS Processor showing one of its double-redundant units is provided in Fig. 3. The unit includes the Central Processor Unit (CPU) based on the 16-bit processor 80C86 operating with 32k×16 PROM and 128k×16 RAM memory. The CPU includes: the System Controller; the Direct Memory Access (DMA) controller, Interrupt Controllers; Address Multiplexer; Task Timer; Watchdog; Non-Maskable Interrupt (NMI) circuitry; and an external Clock Generator. The interfaces are described in detail in the following sub-sections.
Detailed functional block diagram of the ESS processor (nominal unit).
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3.4. Data Management System (DMS) interface
This hardware (HW) interface is based on the recommended circuitry in Experiment Interface Document EID-A. See Section 2.7, page 49, Fig. 2, Fig. 7, Fig. 4, Fig. 5 and Fig. 6, for the Memory Load (ML) interface and the Telemetry Data (TM Data Acquisition) interface. The data transfer protocol is supported in HW by two 8 kword DMA buy naloxone hydrochloride as shown in Fig. 4 which presents block diagrams of the Memory Load Interface (left) and the TM Data Acquisition interface (right).
Memory Load Interface (left) and TM Data Acquisition interface (right) block diagrams.
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The size of the TC DMA (Direct Memory Access) Buffer ensures that a large number of telecommands can be stored here while waiting for processing (from min. 30 TCs up to several hundred TCs, depending on their length). This buffer performs as a circular buffer. The TC processing rate of the ESS software is one per 100 msec – the user must ensure that the buffer does not overflow under these conditions.
The size of the TM (telemetry) DMA Buffer ensures that a maximum size TM block (6144 words) can be read out autonomously by the DMS without SW interaction in the ESS. The process of the TM block transfer is transparent to the SW. This buffer is used as a straight buffer and zygospore is re-written with the next block after the readout is completed.
The ESS supports the Time Synchronisation Service provided by the DMS. The block diagram of the Time Synchronisation Interface is shown in Fig. 5.
Time Synchronisation Interface.
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3.5. Telecom Subsystem Interface
The interface to the Telecom Subsystem (Tx/Rx units) consists of a, bi-directional, bit-synchronous 8 bit communication link (balanced line) for TC data exchange and a, bi-directional, asynchronous 8 bit link (balanced line) for housekeeping (HK)-collection/commanding of the Tx/Rx units. It is important to note that there is no cross coupling provided for RF communication – the nominal ESS works with the nominal Tx/Rx, the redundant ESS works with the redundant Tx/Rx only. See also Section 3.10. Two co-axial relays are used to select which chain is active (one for the receiver and one for the transmitter) – switching these relays is done automatically on powering up the ESS. The status of these relays can be checked in the ESS HK packet (Word 30, bits 5 and 6, refer to the SW User’s Manual).
The ESS hardware provides extensive support for the SW implementation of the Request- To-Send (RTS) protocol (as defined in document ROS-SP-LCOM-ETAN-587-CNES) in terms of pattern recognition logic and various interrupts, as shown in Fig. 6.
Tx/Rx serial interface.
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The HK interface is used for collecting HK data from the Tx/Rx units and to command these units into various modes (based on commands received from ground). Due to the strict timing requirements imposed by the Tx/Rx units, this communication link must be interrupt driven. The ESS uses two dedicated Universal Asynchronous Receiver/Transmitter (UARTs) to perform this function (one for the Rx and one for the Tx unit). A detailed block diagram of this interface is shown in Fig. 7.
Tx/Rx housekeeping interface.
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3.6. The Mechanical Support System (MSS) interface
Control of the MSS by the ESS is implemented in two distinct ways. There are certain functions that are performed by the ESS – such as WAX heater switching, Push Power On/Off and generating the Eject Signal, while other functions are executed by the MSS on receipt of a command from the ESS via its, dedicated, bi-directional bit-synchronous (16 bit) opto-isolated serial interface. A detailed block diagram of this interface is shown in Fig. 8.

Development of Chang e relay

3. Development of Chang’e-3 relay AHDA strategy
The main development direction of AHDA technologies for future Chinese safe planetary landing and sample return missions could be summarized as follows. (1) Inherit the main idea of Chinese Chang’e-3 AHDA system configuration and strategy; (2) Improve the system configuration by using advanced sensors, onboard computer and algorithms; (3) Improve the relay hazard detection and avoidance strategy and mission design for more universal; (4) Transform AHDA problem (including hazard detection, safe landing site selection, and avoidance guidance) into a series of optimal problems and seek corresponding optimal solutions. This section is aiming at providing new conceptual candidate schemes based on the new technologies developed in the next five or ten years.
3.1. Innovative explicit relay AHDA strategy
To differentiate from the subsequent strategy, the “explicit relay AHDA” means it has two real different subsystems design for coarse HDA and precise HDA respectively, they include different sensors and different algorithms for the two HDA’s hazard detection and avoidance guidance, respectively. Uncertain dust haze and sandstorm during landing buy HG-9-91-01 on a Mars-like planet with an atmospheric layer will result in low visibility, which brings new challenges to the Chang’e-3 AHDA scheme [15], [16], [17] and [24]. The aim of this section is to present a candidate conceptual scheme which inherits the typical mode and algorithms of Chang’e-3 AHDA and extends its original applicable scope by replacing the sensors. Especially, (a) the new imaging sensors are required to adapt to almost any lighting conditions and visibility (glare or dark, sandstorm or unclouded); (b) the scheme should not completely relies on optical sensors.
In the new conceptual scheme, as shown in Fig. 11, the infrared imaging sensor is used to replace the optical gray imaging sensor for coarse hazard detection in a large range, while the radar 3D imaging sensor is used to replace the laser 3D imaging sensor for precise hazard detection in a small range. This scheme inherited the relay AHDA strategy and algorithms of Chang’e-3, but the coarse and precise avoidance guidance could be transformed to optimal fuel control problem for further improvement. In addition, the planetary atmospheric characteristics can be analyzed by comparing the real value and prior calibration value of both infrared spectral responsivity and radar wave frequency responsivity, which is conducive to improving the prior atmospheric model data for subsequent missions [3] and [25].
Sketch of innovative explicit relay AHDA.
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Infrared imaging is usually used to detect the target in fog, dust haze, sandstorm and even black night [3], [25] and [26]. First, the infrared imaging is hardly influenced by sunlight angle and lower visibility. It is a well-known fact that the infrared camera is able to normally imaging in shadow areas which relies on better long-distance night vision effect [25] and [26]. But to clarify the application of infrared camera in light areas, in fact, the infrared camera had been successfully preliminary verified by the Yutu lunar rover in Chinese Chang’e-3 mission in light areas [27], [28], [29], [30], [31], [32] and [33]. Its real test result on lunar surface is shown as Fig. 12. It will further be improved and verified in Chinese Chang’e-4 lunar landing mission, the latter is planned to land on the back of the moon before 2020. To clarify the application of infrared camera in dust haze areas (lower visibility), we have also supplement a preliminary test result on the ground.
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Second, the infrared image can also equivalently reflect the light and shadow characteristics of landing area in gray image, so as to compatible with the existing coarse hazard detection algorithm of Chang’e-3 [27], [28], [29], [30], [31], [32] and [33]. Obviously, in unclouded areas, the infrared imaging result is much the same as gray imaging (shown in Fig. 12), because the temperature difference is much the same obvious as the gray difference between shadow and light part in unclouded or vacuum environment. In dust haze areas, the infrared camera is able to penetrate the dust haze and obtain the target areas image (e.g. the mountain is clear in Fig. 13 (right)), but the optical gray camera cannot do that (e.g. the mountain is not clear in Fig. 13 (left)). Therefore, infrared imaging sensor could be considered as a candidate to replace the gray imaging sensor and work at the height of ~2 km above the landing area.
Optical gray imaging (left) and infrared imaging test results (right) on the ground [26].
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Radar 3D imaging sensor has been widely used in Earth observation satellites, various missiles and military aircrafts, which owe to it can obtain the 3D DEM in almost any sunlight angle and visibility conditions, so as to compatible with the existing precise hazard detection algorithm of Chang’e-3 [3], [34] and [35]. Although laser 3D imaging sensor can also provide some level of robustness against slight dust haze and sand storm conditions, but its echo intensity will be degraded through scattering in some serious situations [36] and [37]. Its available range and accuracy will be more influenced than that of the radar 3D imaging sensor, which need to be further improved. On the contrary, the radar wave has more powerful penetrating capacity and better performance in precise HDA for this issue [3], [34] and [35]. Therefore, for an incomplete optical AHDA system, radar 3D imaging sensor could be developed as a candidate to replace the laser 3D imaging sensor and work at the height of ~100 m above the landing area. For a complete optical AHDA system and not worst situations, laser 3D imaging sensor could also be considered.

Reaction time has important influence on the functional

Reaction time has important influence on the functional layer building of NF membranes, and further affects the papain inhibitor performance of NF membranes. The pure water flux of PES blank membrane and the rejection for BSA were 90.0 ± 9.8 L·m? 2·h? 1 and 95.9%, correspondingly. Pure water flux and rejection toward Na2SO4 of the TFC membranes were measured and the results are shown in Fig. 6. With the increase of reaction time, the pure water flux decreases slightly, and the rejection papain inhibitor toward Na2SO4 has no obvious changes. When the reaction time was set as 5 s, the pure water flux of NF hollow fiber membrane was 33.3 L·m? 2·h? 1, and the Na2SO4 rejection was 96.5%. When it reached to 15 s, the flux decreased to 31.2 L·m? 2·h? 1, and the rejection increased to 99.7%. With further increase of time, the flux and rejection remain unchanged basically. These can be explained perennials the functional layer became dense with the increase of reaction time, thus resulted in the decrease of flux and increase of rejection. The suppression effect generated during polycondensation reaction between monomers in different phase with the further increase of reaction time, thus the function layer structure did not change obviously, so the pure water flux and rejection rate remained. It is evident that the optimizing reaction time for polymerization was 15 s.

The purpose of this paper is

The purpose of this paper is to introduce a novel double-pipe AGMD module (DP-AGMD-M). The DP-AGMD-M consisted of daidzin polyvinylidene fluoride (PVDF) hollow fiber membranes and heat exchange capillary copper tubes. In this design, each membrane was inserted into the corresponding copper tube to constitute an independent AGMD unit. Then a certain number of the units were assembled to make up a DP-AGMD-M. And the gap between the outer surface of porous membrane and the inner surface of copper tube acted as the air gap. The air gap width can be evenly distributed and easily regulated in DP-AGMD-M, as shown in Fig. 1b. Thus the heat and mass transfer resistance in AGMD process can be controlled effectively. Meanwhile, another problem in AGMD process is that high membrane distillation flux (J) and high GOR cannot be obtained simultaneously, the true performance cannot be reflected by only J or GOR. So the equivalent membrane distillation flux (JAGMD) was firstly introduced in Hydrophilic groups paper and used to evaluate the comprehensive performance of AGMD process. Tap water was used as feed solution in the experiments. The effect of various parameters on the performance of DP-AGMD-M were experimental investigated. The parameters including the air gap width (da), hot feed temperature (T1), temperature difference (ΔT) between the hot feed outlet temperature and the cold feed inlet temperature, hot feed flow rate (Q) and the effective length of membrane module (L). J, GOR and JAGMD were used to evaluate the performance of DP-AGMD-M.

The choice of membrane material used is

The choice of membrane material used is a very significant determining factor of the efficiency of DCMD [18]. Due to the wide range of DCMD applications such as groundwater, seawater, wastewater, produced water, radioactive water, cooling water, boiler blowdown, and industrial process water treatment, membranes have become increasingly crucial for the overall success of DCMD operations. Hence, depending on the target contaminants present in specific applications, hydrophobic membranes are to be chosen accordingly. Several membranes have recently been designed, fabricated, and tested for process performance using polymers such as PP, PVDF, polysulfone (PSf), and PTFE. PVDF membranes have moderate thermal stability, good chemical resistance with a surface tgf beta receptor 1 of 30.3 × 10? 3 N/m. As for PP membranes, they have a lower membrane performance due to their moderate thermal stability at elevated temperatures and their surface energy is 30.0 × 10? 3 N/m. PTFE membranes are one of the most commonly used membranes in MD. They result in high water vapor permeability and high wetting resistance due to their high porosity, of about 90%, and high hydrophobicity. Their surface energy is the lowest with a value of 9.0 × 10? 3 N/m to 20.0 × 10? 3 N/m [50]. Membranes with low surface energy, high porosity (with low mean pore size and narrow pore size distribution), and low thermal conductivity are most preferred for MD tgf beta receptor 1 applications. Low thermal conductivity of MD membrane is desired to avoid loss of heat across the membrane. The characteristics of polymeric materials that have been tested for DCMD applications in terms of surface energy, thermal conductivity, thermal and chemical stability are summarized in Table 3.