WIND ENERGY POTENTIAL OF COASTAL ERITREA: AN ANALYSIS OF SPARSE WIND DATA

This paper describes an analysis of historical surface wind data for the small country of Eritrea, in northeastern Africa. Winds in this region are directed by summer and winter monsoons in addition to diurnal land–sea effects. An analysis of national Eritrean and historical Italian wind records indicated marginal wind resources in the central highlands near the Eritrean capital of Asmera. An analysis of wind speed records recorded at two sites in the southern port city of Aseb indicate mean annual 10-m wind speeds of 9.5 m s⁻¹ at the windier site. Surface wind speed records for the Red Sea suggest that similar potential may be found along the lower 200 km of the Eritrean coastline. Based on these findings, wind-generated electricity in this region should be substantially cheaper than the current supply generated from imported diesel.     

Thermoelectric Modules Based on Half-Heusler Materials Produced in Large Quantities

Half-Heusler (HH) compounds are some of the most promising candidates among the medium-temperature thermoelectric materials being investigated for automotive and industrial waste heat recovery applications. For n- as well as p-type material, peak ZT values larger than one have been published recently, and first modules have been built. The next step to facilitate the industrialization of thermoelectric module production is upscaling of material synthesis. In this paper, the latest results of the thermoelectric properties of HH compounds produced in kg batches are presented and compared with values published in the literature. The performance of modules built from these materials is analyzed with respect to power output and long-term stability of the material and electrical contacts.     

Deformation of stem cell nuclei by nanotopographical cues

Cells sense cues in their surrounding microenvironment. These cues are converted into intracellular signals and transduced to the nucleus in order for the cell to respond and adapt its function. Within the nucleus, structural changes occur that ultimately lead to changes in the gene expression. In this study, we explore the structural changes of the nucleus of human mesenchymal stem cells as an effect of topographical cues. We use a controlled nanotopography to drive shape changes to the cell nucleus, and measure the changes with both fluorescence microscopy and a novel light scattering technique. The nucleus changes shape dramatically in response to the nanotopography, and in a manner dependent on the mechanical properties of the substrate. The kinetics of the nuclear deformation follows an unexpected trajectory. As opposed to a gradual shape change in response to the topography, once the cytoskeleton attains an aligned and elongation morphology on the time scale of several hours, the nucleus changes shape rapidly and intensely.     

Requirements in performance measurement systems of construction projects from the lean production perspective

Performance measurement (PM) generates useful data for process control, facilitates communication between different sectors, and helps to align efforts on the most important aspects of the business. Thus, PM plays a key role in the management of projects and organizations. PM is also important in the implementation of lean production principles and methods, such as reducing the share of nonvalue-adding activities, increasing process transparency, building continuous improvement into the process, and benchmarking. Moreover, the adoption of the lean production philosophy requires changes in PM. Despite its importance, limited studies have been conducted on the use of PM systems for assessing the impact of lean production programs in construction projects. In addition, studies on how lean companies (or projects) use performance measurement and to what extent the indicators adopted reflect the result of actions that have been undertaken are limited. This study proposes a set of requirements in PM systems of construction projects from the perspective of lean production and a taxonomy of performance metrics for lean production systems. Five empirical studies have been carried out on construction companies from South America involved in the implementation of lean production systems. The scope of this investigation is limited to the construction projects as production systems rather than PM at the level of construction organizations.     

Differences among breast and prostate cancer online support groups

Online support resources have become viable alternatives to face-to-face support groups for cancer patients. It is important to understand how individuals make use of such online support resources and what, if any, differences exist between groups. A content analysis was conducted on 3203 posted messages to prostate and breast cancer support sites on Google Groups and WebMD. Overall, post-treatment survivors were the most common posters followed by spouses; however, the proportion of posters varied by site. For both groups, messages of support were most frequent. However the type of support varied by cancer type. Support messages on the breast cancer sites were mostly offers of emotional support. Conversely, messages of support on the prostate cancer sites focused on informational support. Messages of emotional well-being and medical-related comments were next most common on the breast cancer sites, whereas medical issues and sexual intimacy were on the prostate cancer sites. Overall, these findings identify several key differences in the use and benefits of online support sites for breast and prostate cancer.     

Managing plastic waste from agriculture through reverse logistics and dynamic modeling

Clean Technologies and Environmental Policy - Agrofood companies in the region of southern Sonora, Mexico, including those in Valle del Yaqui, employ agrochemical products (insecticides,...     

Dynamic set point model for driver alert state using digital image processing

Multimedia Tools and Applications - The driver fatigue and lose of attention while driving are the most important causes of traffic accidents. Each year more than one million of deaths occur due to...     

Distribution of Free and Esterified Oxylipins in Cream,Cell, and Skim Fractions of Human Milk

Human milk contains oxylipins involved in infant development. Although oxylipins have been identified in whole or skim milk, their localization within human milk cream, cell, and skim fractions is not known. This study determined the distribution of free and esterified oxylipins in cream, cell, and skim fractions of human milk. Out of 72 oxylipins probed by mass-spectrometry, 42, 29, and 41 oxylipins (free or bound) were detected in cream, cell, and skim fractions, respectively. Over 90% of free and bound oxylipins were derived from linoleic acid in all milk fractions. Other oxylipins were derived from n-6 arachidonic acid and dihomo-gamma-linolenic acid, and n-3 alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid. Free oxylipins were more abundant in skim milk (59.9% of total oxylipins) compared to cream and cell pellet, whereas esterified oxylipins were most abundant in milk cream and cell pellets (74.9–76.9%). The heterogenous distribution of oxylipins in different fractions of human milk may regulate the guided release of these bioactive signaling molecules within infants.     

The Influence of Sepiolite Orientation and Concentration,on the Morphological,Thermal and Mechanical Properties of Bio-Polyamide 4.10 Nanocomposites

Nowadays, trends in automotive sector are toward high-performance materials, but also the concern about the environment has become an important driver for car manufacturers. In this sense, reinforced polymers are lightweight materials that can replace metals in some structural applications with an outstanding contribution to reduce the carbon dioxide emissions. In short fiber-reinforced polymers, processed by injection molding, the fibers are oriented in multiple and arbitrary directions. Due to the arrangement of the fibers, these materials present different thermomechanical behavior. In this study, bio-polyamide 4.10/sepiolite (0–15 wt%) nanocomposites obtained by melt compounding were injected using a square plate mold. Specimens were mechanized in different directions (0°, 45°, and 90°) from this square plate and morphologically and thermomechanically tested. The sepiolite reinforcement results showed improvement in the thermomechanical properties. Moreover, despite the nanometer size of the reinforcement, the mechanical properties were also dependent on the fiber orientation during the injection molding of the nanocomposites. POLYM. ENG. SCI., 60:1035–1043, 2020. © 2020 Society of Plastics Engineers