Design of self-cured geopolymer concrete using Taguchi approach

Geopolymer concrete is the most suitable alternative to conventional concrete. It needs high-temperature curing to achieve better mechanical and durability properties, which is not possible on many Indian construction sites. Therefore, this research explores the effect of Variables like the quantity of aluminosilicate material (ASM), the ratio between Alkaline solution to the quantity of aluminosilicate material (AL/ASM), sodium silicate and sodium hydroxide ratio (SS/SH), and molarity of sodium hydroxide (SH) on the compressive strength and water absorption of Self-Cured Geopolymer Concrete (SCGC). The aforementioned properties have been optimized using the Taguchi approach and non-destructive testing (NDT) has also been performed on SCGC specimens. Along with the experimental work, a mathematical model was also developed using multiple regression analysis for predicting the compressive strength and water absorption of SCGC specimens. SCGC has been developed in an environment where temperature and humidity are not controlled. The experimental results inform that the specimen with ASM of 450 kg/m3, AL/ASM ratio of 0.45, SS/SH ratio of 1.5, and molarity of SH 12M provides maximum compressive strength and minimum water absorption. The pattern of the Signal-to-noise ratio (S/N) curve of the NDT is alike to that of the destructive tests (DT). The findings predicted by the polynomial regression equations are identical to the experimental results compared to the linear regression equation. It has also been found that SCGC of M25 grade can be developed without controlling temperature and humidity. 

Replacement of Natural Aggregates in Geopolymer composites - A brief review

Natural aggregates are essential constituents of both conventional and geopolymer concrete, which fills up approximately 60–80% of the total volume and have a direct impact on the properties of concrete. The extensive use and the high extraction of the natural aggregates raise questions regarding the conservation of natural aggregates' resources and environments. Therefore, several researchers incorporated some recycled aggregates and waste or by-products (WBP) like copper and steel slag, granite quarry sand, crushed sand, etc. as the substitution of natural aggregates. This literature provides a brief review of the properties of the geopolymer composites when natural aggregates are partially or fully replaced. Several previously published literature has been studied and found that the utilization of recycled aggregates and WBP (to a certain extent) into geopolymer concrete has enhanced physical, mechanical, and durability properties, as well as forming a dense structure. Based on the study, it can be concluded that recycled aggregates and WBP have the potential to partially replace natural aggregates (fine as well as coarse)

Superconductivity in 2-2-3 system Y2Ba2Cu2O(8+delta)

Researchers synthesized a new high T(sub c) 2-2-3 superconductor Y2Ba2Cu3O(8+delta) by a special preparation technique and characterized it by ac-susceptibility measurements. Diamagnetism and Meissner effect sets in at low fields and superconducting transition onsets at 90 K. The systematic investigation of the real and imaginary components of ac-susceptibility as a function of temperature and applied ac magnetic field reveals that the magnetic behavior is that of a granular type superconductor

Ayurvedic interventional management of Manyagatavata w.s.r. to Cervical Spondylotic Myelopathy (CSM) - A Case Study

Cervical Spondylotic Myelopathy (CSM) is a degenerative spinal disease which may lead to significant clinical morbidity. The onset of symptoms is usually insidious, with long periods of fixed disability and episodic worsening events. Regarding the pathophysiology of CSM, the repeated injuries to the spinal cord are caused by both static and dynamic mechanical factors. Only limited surgical procedures, neuroplasticity and other medical interventions are employed in modern medicine.  The standard treatment for moderate to severe CSM is operative procedures which are least preferred by the elderly patients. Hence there is a need to search for effective treatment in alternative medicine. According to Ayurveda, cervical spondylosis can be co-related with Manyagatavata, a type of Vataja Vyadhi. A 48 years old male patient presented with Neck pain, neck stiffness, and back pain since 4 years. Here, we are presenting a case of Cervical Spondylotic Myelopathy (CSM) which was treated with Ayurvedic Panchakarma procedures such as Virechana with Mahatikta Ghruta, Tiktaksheera Basti, Greeva Basti, Nasya Karma with Vacha Taila along with Ayurvedic oral drugs like Tab Brihatvata Chintamani Rasa, Ashvagandha Churna with Kavacha Beeja Churna, Amruta Guggula, Ekangaveera Rasa and Chaturbhurja Rasa. These entire drugs were prescribed for twice a day after meals. This case report revealed usefulness of Panchakarma procedures and Ayurveda oral medicines in the management of Manyagatavata w.s.r. to Cervical Spondylotic Myelopathy (CSM)

Collective behavior of stock price movements in an emerging market

To investigate the universality of the structure of interactions in different markets, we analyze the cross-correlation matrix C of stock price fluctuations in the National Stock Exchange (NSE) of India. We find that this emerging market exhibits strong correlations in the movement of stock prices compared to developed markets, such as the New York Stock Exchange (NYSE). This is shown to be due to the dominant influence of a common market mode on the stock prices. By comparison, interactions between related stocks, e.g., those belonging to the same business sector, are much weaker. This lack of distinct sector identity in emerging markets is explicitly shown by reconstructing the network of mutually interacting stocks. Spectral analysis of C for NSE reveals that, the few largest eigenvalues deviate from the bulk of the spectrum predicted by random matrix theory, but they are far fewer in number compared to, e.g., NYSE. We show this to be due to the relative weakness of intra-sector interactions between stocks, compared to the market mode, by modeling stock price dynamics with a two-factor model. Our results suggest that the emergence of an internal structure comprising multiple groups of strongly coupled components is a signature of market development.Comment: 10 pages, 10 figure

SOLID DISPERSION: A NOVEL APPROACH FOR POORLY WATER SOLUBLE DRUGS

Objective: Out of newly discovered drugs more than 40% pharmacologically active molecule having poor solubility. This is one of the serious challenge in the pharmaceutical industry and commercialization of the drug. Methods: With the introduction of new manufacturing technologies such as solid dispersion pH modification, SEED, salt formation, co crystallization. Results: it should be possible to overcome problems. Potential of solid dispersion technology has been well established for hydrophobic agents because of ease of optimization, simplicity and easy scale up. Conclusion: This article begins with an overview of the historical background and definition and importance of solubility and solid dispersion. The remainder of the article is devoted to the production, the different carriers and the methods used for the characterization of solid dispersions

Razine cirkulirajućeg histamina i testovi plućne funkcije u radnika iz predionice pamuka

Circulating histamine level and forced expiratory volume in one second (FEY1) were measured by conventional methods in 39 selected workers (24 exposed and 15 controls) employed in a local cotton mill. There were 12 workers with byssinosis, who complained of breathlessness and tightness in the chest, showed elevated histamine concentrations in blood and a diminished percentage of predicted FEY1 values. Non-byssinotic subjects who were exposed to cotton dust had lower blood histamine concentrations and a higher percentage of predicted FEY1 values. Both exposed groups exhibited enhanced histamine levels and a lower percentage of predicted FEV1 values than unexposed subjects. The circulating histamine concentrations were negatively correlated with FEV1 among exposed workers.Razine cirkulirajućeg histamina i testovi plućne funkcije u radnika iz predionice pamuk

Functional outcome of type 4 Pipkin classification of femoral head fracture operated by open reduction internal fixation by ganz safe surgical dislocation approach management: a case report

Fracture of the femoral head is a severe, relatively uncommon injury; typically, it may have associated with traumatic posterior dislocation of the hip joint with or without acetabulum fracture. The Pipkin classification is the most commonly used classification system. Controversies include the preferred surgical approach (anterior versus posterior) versus ganz safe surgical dislocation approach and whether to perform femoral head fragment excision or internal fixation. Presenting a case report of 28 years old young male with a motor vehicle road traffic accident and suffered a head of femur fracture on right hip joint with posterior wall of right acetabulum fracture with Judet-Letournel type posterior wall and type 4 Pipkin’s classification of femoral head fracture. This patient was undergone for emergency surgical intervention of open reduction, internal fixation through Ganz approach and insertion of Herbert screws for femoral head and interfragmentary screw for trochanteric osteotomy. The patient was followed up for 1 year and have a complete range of motion at hip joint with painless daily lifestyle. Type 4 Pipkin classification of femoral head fracture managed timely and with surgical intervention by ganz safe surgical dislocation approach provides visualization to femoral head and whole acetabulum with internal fixation of femur head by herbert screw which preserves normal anatomic contour of femoral head shows appropriate reduction of fracture fragments and it may also avoid hemiarthroplasty surgeries. Fracture of the femoral head has been associated with a relatively poor functional outcome and requires timely management and surgical intervention. Specially type 4 Pipkin classification of femoral head fracture treated by ganz safe surgical dislocation approach with internal fixation of femur head by herbert screw shows better outcome and avoid risk of AVN of femoral head. Complications associated with fracture of the femoral head and subsequent treatment include osteonecrosis, post-traumatic osteoarthritis, heterotopic ossification and implant failure

Comparative study of functional outcome of distal one-third shaft tibia fractures treated with tip locking tibia nailing versus precontoured anatomical locking plate

Background: The distal 1/3rd shaft tibia extra-articular fractures are treated with both tip locking intra-medullary nailing (TLIMN) and precontoured anatomical locking plates (PCALP). The aim of this study was to compare the results of TLIMN and PCALP in distal tibia fractures and to determine dominant strategies. The complications and functional outcome in both groups were compared. Methods: Forty patients with distal 1/3rd shaft tibia were randomly assigned to TLIMN (group 1) and PCALP group (group 2). The functional outcomes were evaluated using American Orthopaedic Foot and Ankle Society (AOFAS) score. Complications like infection, delayed union, non-union, malunion, hardware prominence and secondary interventions were compared. Results: The average union time was 15.05±3.33 weeks in group 1 and 13.4±2.46 weeks in group 2 (p=0.045). The mean AOFAS score at 1 year follow up was 89.8±6.13 in group 1 and 89.1±6.15 in group 2 (p=0.262). Five patients in group 1 and one in group 2 had mal-alignment. Deep infection was present in one and superficial infection was present in two cases in group 2. Four patients in group 1 developed anterior knee pain and five patients in group 2 had hardware prominence. Conclusions: We conclude that tip locking intra-medullary nail is a reliable and satisfactory method for treatment of fractures of distal 1/3rd shaft tibia AO type 42A, 42B and 42C fractures with good functional outcomes and high union rates with comparatively low complications. Prevalence of malunion was higher in TLIMN group and hardware prominence was more prevalent in PCALP group. Implant removal are more in PCALP group mostly due to implant irritation

Inertial Range Scaling, Karman-Howarth Theorem and Intermittency for Forced and Decaying Lagrangian Averaged MHD in 2D

We present an extension of the Karman-Howarth theorem to the Lagrangian averaged magnetohydrodynamic (LAMHD-alpha) equations. The scaling laws resulting as a corollary of this theorem are studied in numerical simulations, as well as the scaling of the longitudinal structure function exponents indicative of intermittency. Numerical simulations for a magnetic Prandtl number equal to unity are presented both for freely decaying and for forced two dimensional MHD turbulence, solving directly the MHD equations, and employing the LAMHD-alpha equations at 1/2 and 1/4 resolution. Linear scaling of the third-order structure function with length is observed. The LAMHD-alpha equations also capture the anomalous scaling of the longitudinal structure function exponents up to order 8.Comment: 34 pages, 7 figures author institution addresses added magnetic Prandtl number stated clearl