Slip Resistance Test Apparatus of Synthetic Rubber Trackpad on Photovoltaic Surface

The increasing development of the solar energy industry in many countries has led to a rising frequency of human and robot presence in this area. To ensure occupational safety, various protective equipment, including rubber material, is commonly used for slip resistance while moving on the surface of solar PV panels. Therefore, the slip resistance test apparatus is built for testing the slip resistance between the synthetic rubber trackpad and the photovoltaic panel (PV) surface. Synthetic rubber is a man-made material, so it is difficult to control the parameters of its mechanical and chemical properties absolutely. Variations in wet/dry working conditions or Shore hardness are factors that make slip computation more challenging. Therefore, an apparatus with the principle of converting the reciprocating motion of the screw and the casters into the rotation of the hinge is introduced to adjust the tilt angle of the upper surface, detect and evaluate the slippage of the rubber trackpad by sensors. Some parameters related to accuracy such as vibration and theoretical-empirical assessment, are also mentioned. In addition to designing a reliable apparatus, the article also succeeded in providing a safety standard for synthetic rubber with Shore A30-A40 when moving on PV surfaces.Comment: 4 pages, 10 figures, The 20th International Conference on Ubiquitous Robots (UR 2023

INTEGRAL SLIDING MODE CONTROL FOR TRAJECTORY TRACKING CONTROL OF ROBOTIC MANIPULATORS USING AN ADAPTIVE TWISTING ALGORITHM

This paper proposes an integral sliding mode for trajectory tracking control of robotic manipulators. Our proposed control method is developed on the foundation of the benefits in both integral sliding mode control and adaptive twisting control algorithm, such as high robustness, high accuracy, estimation ability, and chattering elimination. In this paper, the proposed integral sliding mode controller is designed with the elimination of the reaching phase to offer better trajectory tracking precision and to stabilize the robot system. To reduce the calculation burden along with chattering rejection, an adaptive twisting controller with only one simple adaptive rule is employed to estimate the upper-boundary values of the lumped uncertainties. Accordingly, the requirement of their prior knowledge is removed and then decrease the computation complexity. Consequently, this control method provides better trajectory tracking accuracy to handle the dynamic uncertainties and external disturbances more strongly. The system global stability of the control system is guaranteed by using Lyapunov criteria. Finally, simulated examples are performed to analyze the effectiveness of our control approach for position pathway tracking control of a 2-DOF parallel manipulator

Analyzing the Transcriptomes of Two Quorum-Sensing Controlled Transcription Factors, RcsA and LrhA, Important for Pantoea stewartii Virulence.

The Gram-negative proteobacterium Pantoea stewartii subsp. stewartii causes wilt disease in corn plants. Wilting is primarily due to bacterial exopolysaccharide (EPS) production that blocks water transport in the xylem during the late stages of infection. EsaR, the master quorum-sensing (QS) regulator in P. stewartii, modulates EPS levels. At low cell densities EsaR represses or activates expression of a number of genes in the absence of its acyl homoserine lactone (AHL) ligand. At high cell densities, binding of AHL inactivates EsaR leading to derepression or deactivation of its direct targets. Two of these direct targets are the key transcription regulators RcsA and LrhA, which in turn control EPS production and surface motility/adhesion, respectively. In this study, RNA-Seq was used to further examine the physiological impact of deleting the genes encoding these two second-tier regulators. Quantitative reverse transcription PCR (qRT-PCR) was used to validate the regulation observed in the RNA-Seq data. A GFP transcriptional fusion reporter confirmed the existence of a regulatory feedback loop in the system between LrhA and RcsA. Plant virulence assays carried out with rcsA and lrhA deletion and complementation strains demonstrated that both transcription factors play roles during establishment of wilt disease in corn. These efforts further define the hierarchy of the QS-regulated network controlling plant virulence in P. stewartii

Draft Genome Assembly of the Entomopathogenic Bacterium Photorhabdus luminescens subsp. sonorensis Caborca

Photorhabdus luminescens subsp. sonorensis strain Caborca is an entomopathogenic bacterium with a dual lifestyle, namely, as a mutualist of the Heterorhabditis sonorensis nematode and a pathogen to a wide range of insect species. The genome assembly, in 231 contigs, is 5.2 Mbp long and includes 25 putative gene clusters for secondary metabolism.College of Agriculture and Life Sciences (CALS) from the University of Arizona; University of Arizona; PERT, NIHUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [K12GM000708]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Differential mRNA expression during QS.

<p>Whole transcriptome data of the <i>P</i>. <i>stewartii</i> DC283 wild-type strain compared to the Δ<i>rcsA</i> strain (panel A) or the Δ<i>lrhA</i> strain (panel B). An open circle is used to represent each gene. Those filled with green are activated (levels of expression are four-fold or lower in the deletion strain) and those filled with red are repressed (levels of expression are four-fold or higher in the deletion strain), by either RcsA (panel A) or LrhA (panel B). The two extreme outlier points, with RPM expression >100 in the wild-type and ~1 in the deletion strains, represent the deleted genes <i>rcsA</i> or <i>lrhA</i>, respectively. All of the other colored points with RPM expression >1 in both samples are tabulated in Tables <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0145358#pone.0145358.t002" target="_blank">2</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0145358#pone.0145358.t003" target="_blank">3</a>. The RPM change of normalized expression for most genes fall tightly around a line of slope of 1, indicating that they are approximately equally expressed in both strains.</p

Validating transcriptional control of select genes by RcsA.

<p>Changes in gene expression were compared between the RNA-Seq analysis (light grey) and qRT-PCR assays (dark grey) for five genes regulated by RcsA. Y-axis represents the fold activation (panel A) or repression (panel B) on a logarithmic scale in the presence of RcsA. RNA-Seq results are averages of two experimental samples and qRT-PCR data represent two experimental samples analyzed in triplicate. Error bars were estimated using the sample standard error of the fold-change across the two independent biological replicates for both RNA-Seq and qRT-PCR.</p

Impact of RcsA and LrhA on phenotype of <i>P</i>. <i>stewartii</i>.

<p>Panel A shows an analysis of capsule production in <i>P</i>. <i>stewartti</i> DC283 wild-type, Δ<i>rcsA</i> mutant and Δ<i>rcsA/rcsA</i>^<i>+</i> complementation strains (left to right). Differences in capsule production are apparent in the regions between the arms of the X-cross streak. Panel B shows an analysis of swarming motility in wild-type, Δ<i>lrhA</i> mutant and Δ<i>lrhA/lrhA</i>^<i>+</i> complementation strains (left to right). All pictures for panel A or B, respectively, were taken at the same magnification after 48 hours of incubation.</p

Model of the quorum-sensing regulatory network in <i>P</i>. <i>stewartii</i>.

<p>See the text for details. Solid lines indicate known direct regulatory control. Dashed lines indicate either direct or indirect control found in the present study. Arrows represent activation and T lines represent repression.</p

Water quality of the Red River system in the period 2012 - 2013: Short communication

Few data are available on the quality of Red river water that is used for multi-purposes, including for domestic water demand in some rural areas. This paper presents the observation results of the Red River water quality in two years 2012 and 2013. The monitoring results showed that the average concentrations of nutrients (N, P) were still far lower than the allowed value of the Vietnamese standard limits for surface water quality (QCVN 08:2008/BTNMT, column A2). Due to the impoundment of two big dams in the Da tributary, the suspended solids contents in river water decreased remarkably. The dissolved heavy metal (DHM) concentrations varied in a high range: Cu: 10 – 80 μg.l-1; Zn: 2 – 88 μg.l-1; Cr: 0.2 – 5.1 μg.l-1; Pb: 2 - 107 μg.l-1; Cd: 2 – 12 μg.l-1; Mn: 2 - 35 μg.l-1; and Fe: 160 – 2370 μg.l-1. Most of the mean values of DHM were lower than the allowed values of the QCVN 08:2008/BTNMT, but at several points of time, several DHM (e.g. Fe, Cd, Pb) contents exceeded the allowed values. The Total Coliform (TC) and Fecal Coliform (FC) densities varied in a high range: TC: 23 to 13,000MPN.100ml-1 and FC: 0 to 1,600MPN.100ml-1 and they exceeded the allowed values QCVN 08:2008/BTNMT at several points observed. The dissolved organic carbon (DOC) contents were in low level and the particulate organic carbon (POC) content mainly derived from soil organic leaching and erosion in the basin. The results underlined the need for regularly monitoring the river water quality, and there should be some effective solutions to manage and treat the waste sources in order to provide safe water for different actual purposes use in the Red River basin.Rất ít số liệu sẵn có về chất lượng nước sông Hồng, dòng sông được sử dụng cho nhiều mục đích, bao gồm cả cung cấp nước sinh hoạt ở một số vùng nông thôn. Bài báo trình bày các kết quả quan trắc chất lượng nước sông Hồng trong hai năm 2012 và 2013. Kết quả quan trắc cho thấy chất dinh dưỡng (N, P) thấp xa so với giới hạn cho phép của tiêu chuẩn Việt Nam về chất lượng nước mặt (QCVN 08: 2008/BTNMT cột A2). Do có hai hồ chứa trên sông Đà, hàm lượng chất rắn lơ lửng trong nước sông giảm đáng kể. Các kim loại nặng hòa tan (DHM) có hàm lượng dao động trong khoảng rộng: Cu: 10-80 μg.l-1; Zn: 2-88 μg.l-1; Cr: 0,2-5,1 μg.l-1; Pb: 2-107 μg.l-1; Cd: 2-12 μg.l-1; Mn: 2-35 μg.l-1; và Fe: 160 - 2370 μg.l-1. Hầu hết các giá trị trung bình của DHM thấp hơn giá trị cho phép của quy chuẩn QCVN 08: 2008/BTNMT, tuy nhiên, tại một số thời điểm, một số DHM (ví dụ Fe, Cd, Pb) có hàm lượng vượt quá giới hạn cho phép. Mật độ tổng coliform (TC) và coliform phân (FC) dao động trong khoảng rộng: TC: 23 đến 13,000MPN.100ml-1 và FC: 0 đến 1,600MPN.100ml-1 và tại một số thời điểm mật độ TC và FC vượt giá trị cho phép của Quy chuẩn QCVN 08:2008/BTNMT. Hàm lượng cabon hữu cơ hòa tan (DOC) ở mức thấp, và hàm lượng cacbon hữu cơ dạng không tan (POC) chủ yếu có nguồn gốc từ đất rửa trôi và xói mòn trong lưu vực. Kết quả quan trắc nhấn mạnh nhu cầu giám sát thường xuyên chất lượng nước sông, và nên có các giải pháp hiệu quả để quản lý và xử lý các nguồn gây ô nhiễm trong lưu vực nhằm cung cấp nước sạch cho các mục đích sử dụng nước sông Hồng như hiện nay