Benchmarking energy utilization in cement manufacturing processes in Nigeria and estimation of savings opportunities

Nigeria is a leading producer of cement in Africa. Because cement production is energy intensive, with significant adverse impacts on the environment, an apparent need exists to assess the Nigerian cement industry to identify energy use mitigation options. The potentials for reducing energy use in typical Nigerian cement manufacturing plants, through the implementation of available energy efficiency measures, were assessed in this study, alongside the attendant costs of implementing those measures. To achieve these, using numerous globally available energy efficiency technologies and measures, energy conservation supply curves were constructed for three Nigerian cement manufacturing plants which operate on wet, semi-wet, and dry cement manufacturing processes, respectively. Comparisons with global best and Chinese benchmark plants with respect to thermal and electrical energy consumption were also made. The comparisons showed that, with respect to the global benchmark plants, thermal energy savings of between 19.83 and 52%, and electrical energy savings of between 35.23 and 43.10%, were possible. With respect to the Chinese benchmarks, thermal energy savings of 10.74–47.32%, and electrical energy savings of 20.95–30.17%, could be achieved. The plants considered performed significantly less than either of the benchmarks in terms of both thermal and electrical energy usage. The energy conservation supply curves for the plants showed that implementing the cost-effective energy efficiency measures could lead to energy savings of about 235,038, 237,913 and 374,055 GJ/year, for the wet, semi-wet, and dry cement manufacturing plants, respectively. Furthermore, technically feasible efficiency measures could yield energy savings of about 250,272, 259,795 and 395,447 GJ/year, respectively. Achieving these savings will improve profitability in the Nigerian cement industry and make the unused energies available for utilization in other sectors of the Nigerian economy.     

Corrosion inhibition and adsorption properties of cerium-amino acid complexes on mild steel in acidic media: Experimental and DFT studies

Abstract

The corrosion inhibition and adsorption behavior of glutamic acid (Glu), glutamine (Gln), and their cerium complexes: cerium glutamate (Ce(Glu)) and cerium glutamine (Ce(Gln)) on mild steel in 0.5?M HCl solutions were studied at 25 and 55?°C and concentration range of 25–200?ppm using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopic (EIS) techniques. The inhibition efficiency was found to be dependent on the concentration and temperature of the system. The potentiodynamic polarization results suggest that the compounds act as mixed-type inhibitors with dominant cathodic inhibition. The mechanism of adsorption deduced from the variation of inhibition efficiency with temperature, as well as the activation parameters, suggest significant physisorption of the inhibitor molecules on the metal surface. The experimental data adhere to the Langmuir and El-Awady et al. kinetic adsorption models. The extent of inhibition was found to be Ce-Gln?>?Gln and Ce-Glu?>?Glu. The scanning electron microscope was employed for the morphological studies and the characteristic of the protective layer on the steel surface verified using UV-Vis spectroscopy and FTIR spectroscopy. Adsorption of the inhibitors on Fe (110) surface was evaluated theoretically.     

Ginsenoside Rf, a trace component of ginseng root, produces antinociception in mice

Ginseng root, a traditional oriental medicine, contains more than a dozen biologically active saponins called ginsenosides, including one present in only trace amounts called ginsenoside-Rf (Rf). Previously, we showed that Rf inhibits Ca2+ channels in mammalian sensory neurons through a mechanism requiring G-proteins, whereas a variety of other ginsenosides were relatively ineffective. Since inhibition of Ca2+ channels in sensory neurons contributes to antinociception by opioids, we tested for analgesic actions of Rf. We find dose-dependent antinociception by systemic administration of Rf in mice using two separate assays of tonic pain: in the acetic acid abdominal constriction test, the ED50 was 56+/-9 mg/kg, a concentration similar to those reported for aspirin and acetaminophen in the same assay; in the tonic phase of the biphasic formalin test, the ED50 was 129+/-32 mg/kg. Rf failed to affect nociception measured in three assays of acute pain: the acute phase of the formalin test, and the thermal (49 degrees C) tail-flick and increasing-temperature (3 degrees C/min) hot-plate tests. The simplest explanation is that Rf inhibits tonic pain without affecting acute pain, but other possibilities exist. Seeking a cellular explanation for the effect, we tested whether Rf suppresses Ca2+ channels on identified nociceptors. Inhibition was seen on large, but not small, nociceptors. This is inconsistent with a selective effect on tonic pain, so it seems unlikely that Ca2+ channel inhibition on primary sensory neurons can fully explain the behavioral antinociception we have demonstrated for Rf.     

Familial essential hypertension and HLA

Ten families living in Shenyang city with multiple cases of essential hypertension were studied by HLA haplotype analysis. They were selected strictly in accordance with the methods of sibling pair analysis and lods analysis. The obtained ratio of HLA haplotype sharing among affected siblings were 28.6%(2): 52.4%(1): 19.0%(0), P > 0.9. It is indicated that the haplotype shared randomly among affected siblings. The results of Lods analysis were Q = 0.40, Lods = 0.046, Pr = 1.112. These results showed that there is no evidence of patients with essential hypertension susceptible to gene linked with HLA.     

Activation of bovine lymphocyte subpopulations by staphylococcal enterotoxin C

Staphylococcus aureus is a major mastitis-causing pathogen in cattle. The chronic nature of bovine staphylococcal mastitis suggests that some products or components of S. aureus may interfere with the development of protective immunity. One class of molecules that could be involved are superantigens (SAgs). Although a significant number of mastitis isolates produce SAgs, the effect of these molecules on the bovine immune system is unresolved. To determine if immunosuppression caused by SAgs could play a role in pathogenesis, we monitored bovine lymphocytes exposed to staphylococcal enterotoxin C1 (SEC1). Activation of bovine lymphocytes by either SEC1 or concanavalin A (ConA) was influenced by the gammadelta/alphabeta T-cell ratio in the culture. Compared to ConA-induced stimulation, cultures stimulated with SEC1 generated small numbers of CD4+ alphabeta T cells expressing high levels of interleukin-2 receptor alpha chain (IL-2R alpha) and major histocompatibility complex class II (MHCII), suggesting that SAg exposure does not lead to full activation of these cells. This state of partial activation was most pronounced in cultures with a high gammadelta/alphabeta ratio. In contrast, significant numbers of CD8+ alphabeta T cells expressed high levels of IL-2R alpha and MHCII, regardless of the gammadelta/alphabeta ratio and the stimulant used. CD8+ blasts in cultures stimulated with SEC1 also expressed another activation marker, ACT3, previously detected predominantly on thymocytes and CD4+ T cells. Although gammadelta CD2- and CD2+ T cells expressed MHCII and IL-2R alpha following stimulation with SEC1, only a few cells increased to blast size, suggesting that they were only partially activated. The results suggest ways in which SAgs might facilitate immunosuppression that promotes the persistence of bacteria in cattle and contributes to chronic intramammary infection.     

Octoxynol presence in bear-bile

The presence of octoxynol from dried bear-bile was examined. Octoxynol was coextracted when glycolipids by Folch-Suzuki partition method. Octoxynol formed mixed-micelles with glycosphingolipids. The glycolipids were purified by DEAE-Sephadex A-25 column chromatography. The fractions containing mixed micelles were obtained from linear gradient solvent of 0.05M-0.5M ammonium acetate in methanol. HPLC ( Bondapak-NH(2) - linked to a Bondapak-C(18) column) chromatogram showed five peaks. Two possible structures for the fourth peak fraction were proposed as (CH(3))(3)C-CH(2)-C(CH(3))(2)-C(6)H(4)-OR and (CH(3))(3)C-C(CH(3))(2)-CH(2)-C(6)H(4)-OR by NMR spectroscopy. The structure was further confirmed by electrospray tandem mass spectrometry (ESI MS/MS). The spectrum showed a protonated molecule at m/z 559 and three different series of ions with mass difference of 44 were detected in the MS/MS spectrum. Therefore, the structure of the fourth peak fraction from HPLC was confirmed as octoxynol, (CH(3))(3)C-CH(2)-C(CH(3))(2)-C(6)H(4)-(OCH(2)-CH(2))n-OH, based on mass spectrometry and NMR spectroscopy.     

Ontario bulk milk somatic cell count reduction program: progress and outlook

The objective of this study was to describe the results of the ongoing somatic cell count (SCC) reduction program in Ontario, Canada and to provide an outlook regarding the possible scenarios beyond the final stages of the current reduction program. The data were from all of the approximately 9500 farms in the province of Ontario during the last 10 yr and included monthly data for kilograms of milk sold, mean milk component measurements, and milk quality measurements (bulk milk SCC, plate loop count, and inhibitor presence). Four of five steps in the control program had a significant impact on the mean monthly bulk milk SCC. The total decrease in mean SCC that was attributable to the program was approximately 80 x 10(3) cells/ml. The monthly occurrence of inhibitor violations increased significantly. Cross-classification of the annual mean bulk milk SCC and the incidence of inhibitor violations indicated that the incidence specifically increased for farms with a relatively high bulk milk SCC. In 1994, bulk milk SCC increased, primarily because of farms that had a mean bulk milk SCC between 150 x 10(3) and 450 x 10(3)/ml. The small relative contribution of farms with higher bulk milk SCC was due to their relatively low production and the small number of farms in those classes. The Ontario SCC reduction program was initially successful in the reduction of mean bulk milk SCC. Further reduction will require the active participation of farms with a relatively low bulk milk SCC. Not only is it necessary to penalize farms that exceed thresholds, but also an incentive to prevent farms with good udder health management from increasing bulk milk SCC is of great importance. The increase in inhibitor violations is of concern and requires further attention.     

The Homothorax homeoprotein activates the nuclear localization of another homeoprotein, extradenticle, and suppresses eye development in Drosophila

The Extradenticle (Exd) protein in Drosophila acts as a cofactor to homeotic proteins. Its nuclear localization is regulated. We report the cloning of the Drosophila homothorax (hth) gene, a homolog of the mouse Meis1 proto-oncogene that has a homeobox related to that of exd. Comparison with Meis1 finds two regions of high homology: a novel MH domain and the homeodomain. In imaginal discs, hth expression coincides with nuclear Exd. hth and exd also have virtually identical, mutant clonal phenotypes in adults. These results suggest that hth and exd function in the same pathway. We show that hth acts upstream of exd and is required and sufficient for Exd protein nuclear localization. We also show that hth and exd are both negative regulators of eye development; their mutant clones caused ectopic eye formation. Targeted expression of hth, but not of exd, in the eye disc abolished eye development completely. We suggest that hth acts with exd to delimit the eye field and prevent inappropriate eye development.     

Ex vivo generation of functional dendritic cells from mobilized CD34+ hematopoietic stem cells

Gene engineering to enhance tumour immunogenicity and elicit curative responses against established tumours and tumour recurrences has become an attractive prospect. Gene engineering enables new genes to be selectively inserted into the genome of a tumour cell, or the construction of new fusion plasmids coding tumour antigens and immunomodulatory molecules. The rationale behind current research is to enhance the immune recognition of tumour antigens through their association with the molecules on which immune recognition depends. The immunotherapy data obtained in many experimental tumour systems provide a realistic assessment of the potential and limits of this technological approach. Experimental vaccination of rodents has been shown to induce a significant immune memory, even against poorly immunogenic tumours, that can prevent tumour growth and cure initial metastases, but is poorly effective against established tumours. Its use in tumour prevention is a fresh dawning perspective.