Opportunities of waste heat recovery from various sources: Review of technologies and implementation.

Waste heat recovery (WHR) using conventional technologies can provide appreciable amounts of useful energy from waste heat (WH) sources, thus reducing the overall energy consumption of systems for economic purposes, as well as ameliorating the impact of fossil fuel-based CO2 emissions on the environment. In the literature survey, WHR technologies and techniques, classifications and applications are considered and adequately discussed. The barriers affecting the development and utilization of systems of WHR, as well as possible solutions are presented. Available techniques of WHR are also discussed extensively, with a particular interest in their progressive improvements, prospects, and challenges. The economic viability of various WHR techniques is also taken into account considering their payback period (PBP), especially in the food industry. A novel research area wherein the recovered WH of flue gases from heavy-duty electric generators was utilized for agro-products drying has been identified, which may be useful in the agro-food processing industries. Furthermore, an in-depth discussion on the appropriateness and applicability of WHR technology in the maritime sector is given a prominent touch. In many review works involving WHR, different areas such as WHR sources, methods, technologies, or applications were discussed, albeit not in a comprehensive way touching on all-important aspects of this branch of knowledge. However, in this paper, a more holistic approach is followed. Furthermore, many recently published articles in different areas of WHR have been carefully examined and the recent findings provided are presented in this work. The recovery of waste energy and its utilization is capable of significantly dropping the level of production costs in the industrial sector and harmful emissions to the environment. Some of the benefits derivable from the application of WHR in the industries may include a reduction in energy, capital, and operating costs, which translate to reduced cost of finished products, and the mitigation of environmental degradation through the reduction of the emission of air pollutants and greenhouse gases. Future perspectives on the development and implementation of WHR technologies are presented in the conclusions section.

Environmental stress and livestock productivity in hot-humid tropics: Alleviation and future perspectives.

Tropical environments are characterized by persistently high temperature and relative humidity and the harsh environmental conditions pose a serious limitation on the optimal performance of the animals raised in this region. Heat stress causes deleterious effects on welfare, immunology and physiology of farm animals with a resultant impact on their productivity as the use of body resources is re-organized and the metabolic priorities of animals shift away from production, growth, health and reproduction. It is imperative to understand the mechanisms involved in the thermoregulation of animals under tropical conditions in order to develop appropriate strategies for their improvement. This review focuses on the available data on the increasing global temperature and the adverse impact of tropical conditions on animals' adaptive mechanism affected during thermal stress on production performance, intestinal and ileal microbiome, physiological responses, antioxidant system, metabolic responses, cellular and molecular response, adaptive mechanism strategies to heat stress and also strategies to palliate environmental stress on livestock under humid tropical conditions including environmental manipulation, genetic opportunity, epigenetic and feeding modification. Overall, the present review has identified the disturbance in the physiological indices of tropical livestock and the need for concerted efforts in ameliorating the adverse impacts of high ambient temperature aggravated by high humidity on livestock in tropical environments. Further research is needed on genotype-by-environment interaction on the thermotolerance of different livestock species in the tropics.

Estimates of aquifer geo-hydraulic and vulnerability characteristics of Imo State and environs, Southeastern Nigeria, using electrical conductivity data.

Two hundred and twenty-six vertical electrical sounding (VES) data were acquired across the study area that has six geologic formations for the purpose of evaluating the geo-hydraulic potentials and the protective capacity of the aquifers of the study area. Schlumberger array was adopted for data acquisition using the ABEM™ Terrameter SAS 4000. Results of the study revealed four to six geo-electric layers. A variety of geo-electric curve types were identified in the study area with the KK curve type being dominant. The aquifer zones lie between the third and sixth layers with their resistivity values ranging from 101 to 8900 Ωm with a mean value of 1799 Ωm. Estimates of the aquifer hydraulic characteristics using the new set of model equations based on conductivity data revealed hydraulic conductivity range of 0.925 and 13.42 m/day while transmissivity ranged between 16.0 and 887 m2/day. These findings showed that groundwater potential is high in Benin Formation, moderate in Nsukka and Ajali Formations, and generally poor within Ogwashi and Imo Shale Formations. Aquifer vulnerability studies revealed that the values of the integrated electrical conductivity (IEC) of the study area ranged between 28.4 and 2202 mS with a mean value of 403 mS. Results of the IEC revealed that the aquifer protective capacity of most parts of the study area were extremely poor (86.2%) with percolation period of several months while only 1.8% of the study area are fairly good. The aquifers of the study area may therefore be vulnerable to contamination from anthropogenic sources, and adequate aquifer protective strategies are therefore recommended.

A successful pregnancy in a Turner syndrome with oocyte donation.

Advances in reproductive medicine using oocyte donation have made it possible for women with Turner syndrome (TS) to achieve successful pregnancies. These pregnancies carry substantial fetal and maternal risks, with hypertensive disorders or pregnancy and fetal growth restriction common, and an increased risk of aortic dissection, sometimes fatal, for the woman. Careful prepregnancy assessment and fetal and maternal vigilance during pregnancy is a necessary prerequisite for a successful outcome. We present a case of a woman with Turner syndrome achieving a successful pregnancy from donor oocyte and review the relevant literature.

Evaluation of the effectiveness and compliance of intermittent preventive treatment (IPT) in the control of malaria in pregnant women in south eastern Nigeria.

Controlling malaria in pregnancy has been an important component of the millennium development goal and intermittent preventive treatment (IPT) is considered an important tool in controlling malaria among pregnant women. In this study, we evaluated the level of compliance to IPT use as well as its effect on malaria infection among pregnant women attending antenatal clinic in south eastern Nigeria. Peripheral blood smears and placental histology were used as diagnostic tools to determine infection rate. Our data show that compliance to IPT use was poor (33%) when compared with non-compliance (67%). Infection rate was significantly lower among IPT users (39%) than in non-users (71%) (X(2) = 39·95; P<0·05). Maternal anaemia was also lower in IPT users (4%) than in non-users (18%). Taken together, IPT use appears to be important in reducing infection rate and maternal anaemia. Therefore, its adoption is highly recommended and this could be improved through public enlightenment campaign and adequate funding.

Mercuric ion inhibition of eukaryotic transcription factor binding to DNA.

Mercury has harmful effects in both rodents and humans. In rodent tissue culture cells exposed to HgCl(2), the metal ions were observed to concentrate in cell nuclei and to associate with chromatin. Thus, transcription factors and other proteins associated with chromatin are possible targets of mercuric ion toxicity. In this study, mercuric ions were found to inhibit the DNA binding activity of the Cys(2)His(2) zinc finger proteins transcription factor IIIA (TFIIIA) and Sp1. These factors are prototypes of the largest eukaryotic protein superfamily. Neither the presence of excess zinc ions nor beta-mercaptoethanol prevented inhibition by mercuric ions. Mercuric ions also inhibited DNA binding by the non-zinc finger protein AP2. Zinc finger-DNA binding was inhibited when both TFIIIA/5S RNA complex and TFIIIA alone were preincubated with concentrations as low as 15 microM mercuric ion. Inhibition occurred in less than 1 min and was not readily reversible. Mercuric ions also inhibited the digestion of DNA by the restriction enzymes BamHI or EcoRI. Inhibition of transcription factors as well as potentially other DNA binding proteins by micromolar concentrations of mercuric ion suggests additional biochemical mechanisms for mercury toxicity in promoting disease via alterations in gene transcription patterns.

Is fetal gender significant in the perinatal outcome of pregnancies complicated by placental abruption?

Seventy cases of placental abruption were studied. These occurred in 12,800 deliveries, an incidence of 4.8 per 1000. There were more female infants (34-56%) compared with males (27-44%). Sixteen infants were stillborn and one baby died in the neonatal period. Thirteen of the perinatal deaths occurred in male infants. We speculate that a higher metabolic rate in male infants may account for this sex difference.

The fetal outcome in pregnancies with isolated reduced amniotic fluid volume in the third trimester.

Our aim was to assess the outcome of pregnancies where oligohydramnios, defined by a published gestational reference range for amniotic fluid index, was the only abnormal finding at third trimester scan, and all other ultrasound parameters including biometry were within normal limits at initial scan. A retrospective case-control study was performed at The Liverpool Maternity Hospital. 103 pregnancies with reduced amniotic fluid index in the third trimester and apparently normal fetal growth profile ultrasonographically were identified from ultrasound reports throughout 1993. Pregnancies in the third trimester with normal amniotic fluid index on index scan were also identified from these reports and 103 were matched for parity, gestational age at delivery, mode of onset of labour, presentation at labour and medical conditions. Exclusion criteria were ruptured membranes, fetal abnormalities, estimated fetal weight below the fifth centile at index scan and multiple pregnancies. The outcome criteria were birthweight, Apgar scores at delivery, induction and emergency delivery for fetal reasons and admission to Neonatal Intensive Care Unit. Statistical analysis was performed by Fisher's exact test and Gart's odds ratio. Compared with controls, pregnancies in the reduced liquor group had a higher number of babies below the 5th centile (odds ratio 5.2, 95% confidence interval 1.6 to 22), a higher risk of induction for fetal reasons (odds ratio 34.4, 95% confidence interval 5.35 to 1425.5) and admission to Neonatal Intensive Care Unit (odds ratio 9.77, 95% confidence interval 1.3 to 432). Any observed difference in the need for emergency delivery due to fetal reasons was not clinically significant (odds ratio 2.16, 95% confidence interval 0.77 to 6.6) The definition used for oligohydramnios used in this study appears to identify a group of babies with a fourfold risk of low birthweight and a high risk of admission to the Neonatal Intensive Care Unit and induction of labour for fetal reasons. This would suggest that pregnancies with isolated oligohydramnios require some form of fetal monitoring and further prospective studies are required to determine the most appropriate method.

Rupture of pregnancy in the communicating rudimentary uterine horn at 34 weeks.

Pregnancy in the rudimentary horn is rare and represents a form of ectopic gestation. Despite advances in ultrasound, prenatal diagnosis remains elusive, with confirmatory diagnosis being made at laparotomy. Because of variable muscular constitution of the wall of the rudimentary horn, pregnancy can be accommodated until late in pregnancy, when rupture occurs manifesting commonly as acute abdomen with high risk of maternal mortality. The rudimentary horn may or may not communicate with the uterine cavity with majority of cases being non-communicating. We present a case of pregnancy in the communicating horn that was difficult to diagnose which ruptured at 34 weeks and a review of literature.

Outcome of ruptured uterus at University Teaching Hospital Aleppo, Syria.

A 10-year review of ruptured gravid uterus at the University Teaching Hospital, Aleppo, Syria showed an incidence of one ruptured uterus in 565 deliveries. This is an average figure compared with published studies but is still high compared with developed countries. Sixty-four per cent of the cases of ruptured uterus had no antenatal care. It is no surprise therefore that maternal and fetal mortality was highest amongst the unbooked labouring women. In survivors the morbidity was also higher. Ruptured uterus is therefore a major cause of maternal and perinatal mortality and morbidity in Syria. The overall hospital maternal and perinatal mortalities for the period under review were 4.3% and 2.6% respectively. The main risk factor identified is scarring from previous caesarean sections. Other risk factors are discussed.