Efficacy of iron fortification compared to iron supplementation among Vietnamese schoolchildren

Background  

Parents of six children are facing a trial on charges of aggravated manslaughter in the care a 5 1/2 month old infant who died suddenly and neglect of their four older children for causing them to be malnourished by feeding them all an exclusively raw foods vegan diet. Both parents declined plea bargains and plan to defend themselves in court.     

Optimization-based cosmetic formulation: Integration of mechanistic model,surrogate model,and heuristics

Multiple functional and hard-to-quantify sensorial product attributes that can be satisfied by a large number of cosmetic ingredients are required in the design of cosmetics. To overcome this problem, a new optimization-based approach for expediting cosmetic formulation is presented. It exploits the use of a hierarchy of models in an iterative manner to refine the search for creating the highest-quality cosmetic product. First, a systematic procedure is proposed for optimization problem formulation, where the cosmetic formulation problem is defined, design variables are specified, and a set of models for sensorial perception and desired product properties are identified. Then, a solution strategy that involves iterative model adoption and two numerical techniques (i.e., generalized disjunctive programming reformulation and model substitution) is applied to improve the efficiency of solving the optimization problem and to find better solutions. The applicability of the proposed procedure and solution strategy is illustrated with a perfume formulation example.     

Influence of process parameters on the deposition footprint in plasma-spray coating

This paper presents an investigation of the influence of plasma spray process conditions on the in-flight particle behavior and their cumulative deposition to form a coating on the substrate. Three-dimensional computational fluid dynamics (CFD) analyses were performed to model the in-flight particle behavior in the plasma-spray process and their deposition on the substrate. The plasma spray was modeled as a jet issuing from the torch nozzle through the electrical heating of the arc gas. In the model, particles were injected into the plasma jet where they acquired heat and momentum from the plasma, some got melted and droplets were formed. By means of a droplet splatting model, the particle in-flight data generated by the CFD analyses were further processed to build up an imaginary three-dimensional deposition profile on a flat stationary substrate. It is found that the powder carrier gas flow rate influences the particle distribution on the substrate by imparting an injection momentum to the particles that were directed radially into the plasma jet in a direction perpendicular to the plasma jet. The larger sized particles will acquire higher injection momentum compared with the smaller sized particles. This causes particle distribution at the substrate surface that is elliptical in shape with the major axis of ellipse parallel to the particle injection port axis as illustrated in Fig. 1. Larger particles tend to congregate at the lower part of the ellipse, due to their greater momentum. The distribution of particle size, temperature, velocity, and count distribution at the substrate was analyzed. Further, based on the size and the computed particle temperature, velocity histories, and the impact sites on the substrate, the data were processed to build up a deposition profile with the Pasandideh-Fard model. The shapes of deposition profiles were found to be strongly driven by the segregation effect.     

形变诱发马氏体对1Cr18Ni9Ti不锈钢应力腐蚀破裂的影响

通过低温(-70℃)拉伸方法,制备出具有不同马氏体(铁磁相)含量的1Cr18Ni9Ti(AISI321)奥氏体不锈钢试件。采用恒载荷法对双边缺口试样进行应力腐蚀试验,测定了不同马氏体含量的试样在氯化物介质中应力腐蚀破裂(SCC)的归一化门槛值。用SEM观察断口形貌。结果表明:当铁磁相含量小于5%时,材料的SCC敏感性随含量增加而减小;在5～15%范围内,SCC敏感性不断增加;在15～24%区域中,材料的SCC敏感性迅速下降;超过24%,SCC敏感性又有所上升。     

An underwater acoustic MAC protocol using reverse opportunistic packet appending

Underwater communication primarily utilizes propagation of acoustic waves in water. Its unique characteristics, including slow propagation speed and low data rates, pose many challenges to Media Access Control (MAC) protocol design. In most existing handshaking-based underwater MAC protocols, only an initiating sender can transmit data packets to its intended receiver after a channel reservation through a Request-to-Send (RTS)/Clear-to-Send (CTS) handshake. This conventional single-node transmission approach is particularly inefficient in underwater environments, as it does not account for long propagation delays. To improve channel utilization in high latency environments, we propose a novel approach that exploits the idle waiting time during a 2-way handshake to set up concurrent transmissions from multiple nodes. The sender can coordinate multiple first-hop neighbors (appenders) to use the current handshake opportunity to transmit (append) their data packets with partially overlapping transmission times. After the sender finishes transmitting its packets to its own receiver, it starts to receive incoming appended packets that arrive in a collision-free packet train. This not only reduces the amount of time spent on control signaling, but it also greatly improves packet exchange efficiency. Based on this idea, we propose an asynchronous, single-channel handshaking-based MAC protocol based on reverse opportunistic packet appending (ROPA). From extensive simulations (single- and multi-hop networks) and comparisons with several existing MAC protocols, including MACA-U, MACA-UPT, BiC-MAC, Slotted-FAMA, DACAP, unslotted Aloha, we show that ROPA significantly increases channel utilization and offers performance gains in throughput and delay while attaining a stable saturation throughput.     

Ketamine effects on the urogenital system--changes in the urinary bladder and sperm motility

Different doses of ketamine (10 mg/kg, 20 mg/kg, 30 mg/kg, 40 mg/kg, 50 mg/kg, and 60 mg/kg) were injected i.p. (I.P.), respectively, to male ICR mice to determine the optimal dosage for chronic administration. At and above 40 mg/kg I.P. injection, mice had almost no hindlimb movement during swimming test. Subsequently, 30 mg/kg was used as the dose for the study in the toxicity of long-term ketamine administration on urinary bladder and sperm motility. The treatment group were subdivided into two (n = 10 each group); one received daily ketamine treatment i.p. for 3 months and another group for 6 months. Corresponding number of mice in control groups (n = 5 each group) received saline injection instead of ketamine. Terminal dUTP nick and labeling (TUNEL) study and Sirius red staining were carried out on the sectioned slides of the urinary bladders to study the degree of apoptosis in both epithelium and muscular layers of the urinary bladder and the relative thickness of the muscular layers in this organ was also computed. Apoptosis in the bladder epithelium was observed initially in the 3-month ketamine treated mice and the number of apoptotic cells was significantly different (P < 0.05) between the 3-month and 6-month ketamine treated mice and the control. The relative thickness of muscular layers in the bladder wall also decreased significantly (P < 0.05) when the 6-month treated mice and the control were compared. Sirius red staining revealed increase of collagen in the urinary bladder of the treated mice, most evidently 6 months after ketamine treatment. In addition, the sperm motility was studied and there was a statistically significant difference between the control and ketamine treated groups in the percentages of sperms which were motile (P < 0.05). This suggested that the chronic administration of ketamine affected the genital system as well.     

“Area Without Numbers”: Using Touchscreen Dynamic Geometry to Reason About Shape

Abstract

In this article, we report on two lessons aimed at introducing junior high school students to the idea of shearing in a touchscreen dynamic geometry environment. By using shearing, we hoped to shift students’ attention away from a formula-driven, computational conception of area toward a more geometric one. We found that the students were able to solve several problems involving the comparison of polygons based on verbal and diagrammatic explanations. We describe the features of the touchscreen dynamic geometry technology that supported their learning, as well as the specific role that the teacher played in modeling students’ reasoning about area.