Development of testing methods for comparative assessment of Thin Spray-on Liner (TSL) shear and tensile properties.

Spray-on linings in the form of shotcrete have been in use in the mining industry for the past 60 years. The introduction of Thin Spray-on Liners (TSLs) in mining has been more recent (approximately 20 years). There is no doubt that TSL technology, although it has great potential for success, will go through an extremely difficult implementation period as was experienced by shotcrete. Publications describing successful TSL application experiences have started to emerge. However, confusion and carelessness regarding standards, specifications, and design guidelines around the world will have to be addressed to overcome the teething problems experienced by the new TSL technology. There are still many aspects of TSLs that need to be investigated to provide information necessary to formulate a proper TSL design. This thesis is intended to bridge some of the knowledge gaps existing in the area of the mechanical property testing of TSLs. A literature review provides the background to the concept of TSL technology and gives a summary of the previous testing methods performed to date. The shortcomings of these testing methods are emphasised and their applicability as standard testing methodologies is discussed. In the absence of sound test methods, the assessment of TSL suitability and performance is mainly based on opinion or short term visual observations at mine sites. The description and reporting of previous testing on TSLs, in general, have not been done appropriately and have often been found to lack critical information. Therefore, the absence of generally agreed testing methods results in a lack of parameters which are important in evaluating the quality and performance capabilities of available TSL products. For this reason, the development of appropriate and acceptable testing methods for TSLs is urgently needed so that design standards and requirements can be formulated. This thesis focuses on four laboratory testing methods. The development of two new laboratory testing methods for the quantification of mechanical properties of TSLs is described, namely, shear-bond strength testing and material shear strength testing. In addition, two other existing testing methodologies were adopted with minor modifications and included in the TSL testing programme. These are material tensile strength testing and tensile-bond strength testing. Large numbers of tests were carried out for each method as part of the research described. The results of all four testing methodologies have been collated and analysed in an attempt to make the comparison of the mechanical properties of various TSLs and shotcrete possible. Each of the four testing methodologies is allocated a single chapter of the thesis, with particular focus on the details of the test considerations, and descriptions of apparatus, specimen preparation and test procedures. The results of testing are provided and analysed for the comparison of TSL performance in each of these chapters. A collective and comparative analysis and discussion on the test results is included. Approximately 4000 tests were performed on 32 TSL products from 12 companies as well as one brand of plain shotcrete. Various factors such as temperature, humidity, substrate type and condition, rate of loading, specimen size, and storage duration significantly influence the performance of TSLs. All of these factors were considered, but their values or conditions remained fixed in the testing programme to limit the number of tests. However, an exception was the curing time, which was selected as the main test variable. Curing times from 1 day to 28 days were used in all the tests. Subsequent analysis of the test results for the new testing methods provides a comparison of TSLs based on the measured strength properties. Comparison of TSL with shotcrete strength has also been possible through the same test methods, which have not been performed on shotcrete before. The test results also show an obvious strength increase with increasing curing time as expected. The simplicity and ease of performing these tests and the easy understanding of results compared with previous TSL testing has assisted in their general acceptance. The response from the mining industry and the product manufacturers towards the testing methodologies developed under the scope of the research in this thesis has been positive. The test results have been well received and have been used with confidence in the selection, quality control and comparative assessment of TSLs. The extensive laboratory testing programme and the development of two new laboratory testing methods for TSLs, described in this thesis are considered to be a significant contribution to the state of the art of TSL technology. The database of test results and findings from this research can be used by liner manufacturers as a reference for the comparison of their products. Further improvements and development of new TSL products with better qualities will then assist in the further implementation of TSLs in the mining and civil engineering industries

Erzincan Yöresinde Organik Kuru Fasulye (Phaseolus Vulgaris L.) Üretiminin Araştırılması

Proje 2005–2007 yılları arasında Erzincan Bahçe Kültürleri Araştırma Enstitüsü arazisinde tarla sistemi şeklinde kurulup yürütülmüştür. Bu araştırmada; Erzincan koşullarında kuru fasulyenin organik olarak yetiştiriciliğinin araştırılması amaçlanmıştır. Yetiştirme sezonu boyunca kültürel bakım işlemleri yapılmıştır. Hastalık ve zararlılar takip edilmiş ve ekonomik zarar eşiğini geçmediği için mücadele yapılmamıştır. Bitkilerde fenolojik ve morfolojik gözlemler alınmıştır. Çalışmada organik uygulama da ortalama 201,31 kg/da, geleneksel uygulama da ise ortalama 208,01 kg/da verim alınmıştır. Baklada tane sayısı ve tane verimi bakımından farklılık çıkmış incelenen diğer özellikler bakımından farklılıkların oluşmadığı görülmüştür. Araştırma da ele alınan farklı iki yetiştiriciliğin uygulanabilirlik durumları incelenmiş ve organik yetiştiriciliğin Erzincan bölgesinde yapılabilir olduğu tespit edilmiştir

THE STATISTICAL ASSESSMENT OF SUBGRADE-SOIL PARAMETERS OF THE COASTAL WAY BETWEEN GUMRUK AND UCKUYULAR-IZMIR AND DETERMINATION OF SOIL PROFILE AT THE SEA-BED

Doğal zeminlerde, zemin parametreleri gerek yer, gerekse de zamana bağlı olarak değişmekte ve rastgele bir özellik göstermektedir. Bu parametrelerin nümerik değerleri genellikle sınırlı bir zemin araştırmasından ve zeminden alınan az sayıdaki örnekten elde edilen laboratuvar deney sonuçlarından tahmin edilmektedir. Bu çalışma, İzmir Körfezi'nin güneyinde Gümrük-Üçkuyular arası sahil yolu sondaj işlerine ait zemin deneylerinin laboratuvar ve arazi SPT deney sonuçlarını kapsamaktadır. Zeminlerin indeks dayanım ve sıkışma parametrelerinin istatistiksel bir değerlendirilmesini de içeren bu çalışma, bölgenin jeoteknik koşulları hakkında genel bir fikir de vermektedir. Bu kapsamda, istatistiksel analiz metotları kullanılarak incelenen zemin jeoteknik parametrelerinin frekans histogramları çizilmiş ve ayrıca, deney sonuçlarına göre bulunan istatistiksel parametreler elde edilmiştir. Arazideki zeminlerin kohezyonlu veya kohezyonsuz oluşlarına göre penetrasyon sayıları derinlik ve su düzeltmeleri uygulanıp mevcut verilerle SPT direnç profili elde edilmiştir. Bu direnç profili deniz tabanında mevcut andezit ana kayasının üzerine uyumsuz olarak gelen ve çevre kayaçlardan türeme genç kuvaterner çökellerine aittir. Deniz sondajlarından elde edilen veriler yardımıyla İzmir Körfezi'nin güney kıyısına ait jeolojik profil elde edilmiş ve mevcut zeminlerin jeoteknik özellikleri tartışılmıştır. In nature, the soil parameters differ according to the place and time, and show a random feature. The numerical values of these parameters are generally examined in a limited soil investigation program and laboratory test results are obtained from a limited number of soil samples. This study includes both the field and laboratory tests results of the soils obtained from the boreholes drilled in the sea shore between Gümrük and Üçkuyular Districts in the south of the Izmir Bay in Western Turkey. A statistical assessment of the index and strength properties of the soils was made to establish the geotechnical properties of this area. The frequency histograms of the related soil parameters were prepared and the statistical parameters were analyzed taking into consideration whether the soil is cohesive or cohesionless. The SPT-Resistance Profile was obtained by applying the water and depth corrections to the field data. This strength profile belongs to that the Quaternary aged sediments, which overlay on the andesitic main rock at the base of the sea, derived from the host rocks. Geological cross-section of the south coast of the Izmir Bay was prepared using the borehole data taken from the boreholes drilled in the sea and geotechnical properties of the soil-groups at the sea-bed have been discussed in this paper

The effects of daylight exposure on melatonin levels, Kiss1 expression, and melanoma formation in mice

Aim To determine how daylight exposure in mice affects melatonin protein expression in blood and Kiss1 gene expression in the hypothalamus. The second aim was to assess the relationship between skin cancer formation, daylight exposure, melatonin blood level, and kisspeptin gene expression level. Methods New-born mice (n = 96) were assigned into the blind group or daylight group. The blind group was raised in the dark and the daylight group was raised under 12 hours light/12 hours dark cycle for 17 weeks. At the end of the 11th week, melanoma cell line was inoculated to mice, and tumor growth was observed for 6 weeks. At the end of the experiment, melatonin level was measured from blood serum and Kiss1 expression from the hypothalamus. Results The blind group had significantly higher melatonin and lower Kiss1 expression levels than the daylight group. Tumor volume was inversely proportional to melatonin levels and directly proportional to Kiss1 expression levels. Tumor growth speed was lower in the blind than in the daylight group. Conclusion Melatonin and Kiss1 were shown to be nvolved in tumor suppression. They were affected by daylight and were mutually affected by each other

Electrically tunable radiative cooling performance of a photonic structure with thermal infrared applications

Thermal infrared (IR) radiation has attracted considerable attention due to its applications ranging from radiative cooling to thermal management. In this paper, we design a multi-band graphene-based metamaterial absorber compatible with infrared applications and radiative cooling performance. The proposed structure consists of the single-sized metal-insulator-metal (MIM) grating deposited on metal/insulator substrate and single-layer graphene. The system realizes a broadband perfect absorption ranging from 940 nm to 1498 nm and a narrowband perfect absorption at the resonance wavelength of 5800 nm. Meanwhile, the absorptivity of the structure is suppressed within the mid-wave infrared (MWIR) and long-wave infrared (LWIR) ranges. Furthermore, to demonstrate the tunability of the structure, an external voltage gate is applied to the single-layer graphene. It is shown that, by varying the chemical potential of graphene layer from 0 eV to 1 eV , the absorption resonances at the mid-infrared (MIR) range can shift toward the shorter wavelengths. It is also observed that the structure can possess an average net cooling power over 18 at the ambient temperature, when is varied from 0 eV to 1 eV. Finally, we investigate the overall performances of the structure as a function of temperature to realize thermal infrared applications.Comment: 11 pages, 6 figure

Characteristics of Covid-19 infection with the original SARS-Cov-2 virus and other variants: A comparative review

The novel coronavirus infection (Covid-19) had enormous effects on global health. Since it first emerged (in China, three more clinically significant variants developed, which were differentiated from the original virus in terms of clinical course, hospitalization, mortality, and overall outcome. These variants are Alpha (British), Delta, and Omicron variants. Each variant was the prominent infectious variant of the Covid-19 virus for a specific time. While some variants were associated with higher mortality, others were associated with a higher spreading rate compared to the rest of the variants. The present review aimed to summarize the clinical characteristics, symptoms, need for hospitalization and intensive care, mortality, and overall outcomes of the original and other three significant variants of the Covid-19 infection. We also aimed to present a brief review of post covid syndrome

The relationship between L-arginine/ADMA ratio and coronary collateral development in patients with low glomerular filtration rate

Background: It is yet to be established which factors are responsible for differences among patients with the same degree of coronary artery disease in terms of coronary collateral development (CCD). Methods: Patients who had a greater than or equal to 95% stenosis in at least one epicardial coronary artery were classified into two groups according to their glomerular filtration rate (GFR) level. Afterwards, the degree of CCD was evaluated according to their plasma concentration of asymmetric dimethylarginine (ADMA) and GFR levels. Results: Rentrop grade 2&#8211;3 was found more frequently in patients with GFR > 60 mL/min than in patients with GFR < 60 mL/min (68.6% vs 41.4%, p = 0.032). Then we divided patients into four groups according to their GFR levels and Rentrop grades; whereas we did not find any significant difference for L-arginine or ADMA levels (respectively p = 0.629 and p = 0.076), we did find a statistically significant difference between groups for L-arginine/ /ADMA ratio (p = 0.003) and this statistically significant difference was evident between patients with GFR 60 mL/min and Rentrop 2&#8211;3 (1.23 vs 1.69, p < 0.001). Multivariate logistic regression analysis revealed that L-arginine/ADMA ratio was the only variable which had a significant effect on CCD (OR = 1.016; 95% CI 1.001&#8211;1.031, Wald = 4.565; p = 0.033). Conclusions: These results showed that CCD was poor in patients with GFR < 60 mL/min, presumably because of the adverse effect of decreased L-arginine/ADMA ratio on endothelial cells and angiogenesis. (Cardiol J 2012; 19, 1: 29&#8211;35

Disseminated tuberculosis with lymphatic, splenic and scrotal abscesses: a case report

Introduction: Disseminated tuberculosis can involve several organs and clinically present with a potpourri of signs and symptoms. Early diagnosis and timely initiation of proper treatment are of great importance in preventing the later complications of the disease. Case presentation: We report a case with disseminated tuberculosis who exhibited a wide spectrum of extrapulmonary involvement. The present case had lung and lymph node tuberculosis with abscess formation and remained undiagnosed for two years. Thereafter, multiple splenic abscesses developed that necessitated splenectomy, and at the final stage, he presented with scrotal abscesses. Conclusion: This paper highlights the diverse clinical appearances of disseminated tuberculosis and the significant importance of early diagnosis and treatment. © 2009 Ayaslioglu et al.; licensee Cases Network Ltd

Testicular Nitric Oxide and Thiobarbituric Acid Reactive Substances Levels in Obstructive Azoospermia: A Possible Role in Pathophysiology of Infertility

Objective. The aim of the study is to evaluate the levels of nitrite/nitrate and thiobarbituric acid reactive substances (TBARS) and their relationship with seminal parameters in experimental obstructive azoospermic rats to explain the possible mechanism of impaired sperm quality in obstructive azoospermia. Methods. A total of 10 male Spraque-Dawley rats underwent bilateral vas resection and ligation (Group-1 = vasectomy group). The findings were compared with control group (Group-2 = sham group, n = 10). Animals were sacrificed 8 weeks after surgery. Testes were removed and used for the evaluation of nitrate/nitrite and TBARS levels and for histology. Epididymal-aspirated seminal plasma was used for semen count and morphological analysis according to the Kruger criteria. Results. Testicular tissue nitrate/nitrite and TBARS levels were 35.7 ± 3.1 μmol/g protein and 3.7 ± 0.1 nmol/g protein in Group-1, and 19.3 ± 0.7 μmol/g protein and 3.1 ± 0.1 nmol/g protein in Group-2, respectively. Both parameters showed statistical differences between the two groups. Testicular tissue nitrate/nitrite and TBARS levels showed negative and statistically significant correlations with sperm motility and morphology. Conclusions. The present study showed that testicular nitrate/nitrite and TBARS levels were increased in obstructive azoospermia. For that reason, we concluded that antioxidant treatment can be recommended to patients before sperm extraction for artificial reproduction due to obstructive infertility after vasectomy reversal

A perspective on university academic workload measurement

Internationally, universities are increasingly seen as being part of the wider community, which has an impact on academic workload. This paper explains the importance of a model for investigating such academic workloads. Quantifying and reporting workloads are complex tasks. Despite this complexity, the model developed at the University of the Witwatersrand’s School of Mining  Engineering gives some insight into the three main components of academic workload, namely lecturing, research and administrative services. Today there is a better understanding of the meaning of workload, the problems to consider when quantifying workloads, the relationship between workload and performance and the issues to consider for staff development. This perspective concludes with lessons learnt over a five-year period