Quick Manual Design of Shell and Tube Heat Exchangers

The purpose of this thesis is to provide a general procedure to, quickly estimate the approximate size of a shell and tube heat exchanger, including multiple shells in series and/or parallel, and dimensions required for entering rating calculations. This procedure is an expansion and refinement of the procedure given in Section 3.1.4 ofthe Heat Exchanger Design Handbook (Bell, 1983). The procedure is useful for a preliminary plant layout, cost estimation, and as a check on the output of computer-based design procedures. Chapter 1 discusses the general usefulness of an approximate design method for shell and tube heat exchangers and describes both the essential and desirable features of such a method. A brief description of the components of a shell and tube heat exchanger, the various types of shell and bundle constructions, and the general selection criteria are also presented. Chapter 2 deals with the basic structure ofthe design method. It includes a brief description of the concepts of conduction, convection and radiation. Also presented are procedures for the estimation ofQ (total heat duty), MTD (mean temperature difference), individual film heat transfer coefficients (a's) and overall heat transfer coefficient (Uo), and the number of shells required to perform the specified duty. The existing version of the design method, with its limitations, is also described. In Chapter 3, the relationship of the heat transfer area, A, to the basic shell dimensions (shell inside diameter and effective tube length) is developed. A. generalization of the outside area/shell dimensions relationship for the reference case to other tube sizes and layouts, bundle types, number of tube side passes and finned tube dimensions is also developed. Chapter 4 presents a procedure for the estimation of tube counts. An approximate method for estimating the baffle cut and baffle spacing as a function of the shell inside diameter is also presented. Vibration limitations are also described. The Summary and Conclusions are given in Chapter 5 and Recommendations in Chapter 6. The use of the approximate design method is illustrated in the form of an example problem in the appendix. Also given are various tables for the estimation of film and overall coefficients for various cases, fouling factors, dimensions of bare and finned tubes and detailed tables and plots for the estimation of the correction factors

Prevention of pathological fracture in fibrous dysplasia of proximal femur in a 24-year-old female a rare presentation - a case report

Fibrous dysplasia (FD) was historically mentioned in the medical literature in 1938 by Dr. Lichtenstein and in 1942 by Dr. Lichtenstein and Jaffe. The term Jaffe-Lichtenstein syndrome is sometimes used synonymously with monostotic FD or to denote cases of polyostotic FD with café au lait spots, but no endocrine dysfunction. Our case is a 24-year-old female, housewife presented to our hospital with a complaints of right hip pain and backache with difficulty in walking of 6 months duration. She had dull aching pain which increased in intensity with the course of time, there was no radiation, but was aggravated by movements. She was managed with dynamic hip screw along with curettage of the lesion and bone graft, after 9 months of follow up, she had no pain over her hip and there was calcification over the previous lesion, our patient had a very favourable outcome

Classifying Consumers Based Upon Their Proenvironmental Behaviour: An Empirical Investigation

Despite a wide applicability of demographic and psychographic variables for segmentation criteria, past research indicates that these variables are not as effective as behavioural variables. The present empirical study’s focus is determining different typologies of Indian consumers, which exist in terms of Pro-Environmental Behaviour (PEB), and investigating whether PEB varies across these typologies. For this study, a total of 152 Indian consumers were contacted through convenience sampling. Using factor and cluster analysis, the typologies were classified as “active green activists” or “passive green activists”. Using discriminant analysis, formed groups were validated and profiled by chi-square. Using environmental variables as the basis of segmentation, this study offers practical guidelines to green marketers who are targeting the Indian markets

There is hope, we can save the planet

This photograph originally appeared in the 2017 Research student photography and image competition held to celebrate National Science Week (18 August - 8 September 2017). Blurb: Carbon footprint "While we were able to enjoy husky run on frozen rivers and glaciers, it highlights the need to reduce our carbon footprint so that future generations can have the same enjoyment. Let us all work to preserve glaciers for future generations. This is the driving force of my research that leads to process cycle time reduction in Injection Moulding and CFRP processing, reducing carbon footprint and improving profits.

Can deceased donor with recurrent primary brain tumor donate kidneys for transplantation?

Kidney transplantation from deceased donors is in its infancy in India. Cadaver organ donation was accepted legally in 1994 by the “Human Organs Transplantation Act.” Marginal donors are now accepted by many centers for kidney transplantation. We report a case of procurement of both kidneys from a young deceased donor having recurrent primary brain tumor, transplanted into two adult recipients with successful outcome

Spontaneous closure of urethrovaginal fistula associated with pelvic fracture

Female urethral injury following pelvic fracture is a rare entity. Due to the absence of large series, management guidelines are still not standardized. Patients can have associated urethrovaginal or vesicovaginal fistula, management of which poses a major challenge to the reconstructive urologist. Spontaneous closure of fistula produced by gynecological or obstetrical injuries have been described in the literature. Spontaneous closure of fistula caused due to pelvic fracture has not been described in the literature

Robotic assisted kidney transplantation

Kidney transplantation is the standard of care for patients with end stage renal disease. While open surgery remains the gold standard, minimally invasive surgery has recently been introduced for the recipient undergoing kidney transplantation. We review the evolution of techniques of minimally invasive surgery for kidney transplantation with specific emphasis on technical aspects of robotic assisted kidney transplantation