The aim of the research was to produce hollow yarn knitted fabrics with improved thermal comfort properties. Thermal comfort properties and utility properties determine the wearing comfort of textiles and the suitability of a new textile product for a particular application. Both, Thermal comfort properties such as thermal absorptiveness, thermal conductivity, air permeability and utility properties like percent stretch, spirality, bursting strength of core yarn knitted fabrics and hollow yarn knitted fabrics were assessed. A new method was proposed and discussed for producing hollow yarns at fabric stage (in this case knitted fabric) which involved the following steps: - a) Production of ring spun yarns, comprising nylon as a core and cotton as a sheath, using Ring Spinning System. b) Production of knitted fabrics of different knit structures viz., single jersey, rib and interlock using above mentioned yarn. c) Dissolution of core element i.e. Nylon into formic acid to obtain hollow yarn knitted fabrics and this hollow yarn knitted fabrics can be tailored for specific end use. The study covers comparative analysis of thermal insulation properties like thermal absorptiveness, thermal conductivity and others for core yarn knitted fabrics and hollow yarn knitted fabrics and the influence of the count of core nylon filament and the type of knit structures on the thermal properties of the fabrics. Based on the results obtained from the work, it can be stated that hollow yarn knitted fabrics offer numerous possibilities for creating fabric properties which influence their comfort of use.

The development of microneedles that penetrate the skin barrier, but are small enough not to stimulate nerves, has the potential to deliver drugs across skin in a painless way. Controlled injection by convective flow into skin using hollow microneedles, however, has remained a challenge. To address this challenge, the goals of this study were (i) to provide experimental measurements coupled with numerical simulations to quantitatively describe fluid mechanics of flow within microneedles over a range of experimental conditions and needle geometries, (ii) to demonstrate and study the effects of diffusion-based delivery of insulin to diabetic rats in vivo using solid and hollow microneedles and (iii) to determine the effect of experimental parameters on microinfusion through hollow microneedles into skin to optimize drug delivery protocols and identify rate-limiting barriers to flow. Experimentally, we quantified the relationship between pressure drop and flow rate through microneedles as a function of fluid viscosity and microneedle length, diameter, and cone half-angle. Microneedle tip diameter and taper angle were the primary controlling parameters for flow through conically tapered microneedles as shown by numerical simulations. Flow rates over a range of 1.4 56 l/s were achieved through microneedles (in the absence of skin) with pressure drops in the range of 4.6 196.5 kPa. This work also studied the use of solid and hollow microneedle arrays to insert into the skin of diabetic animals for transdermal delivery of insulin. Blood glucose levels dropped by as much as 80% in diabetic rats in vivo. Larger drops in blood glucose level and larger plasma insulin concentrations were shown due to higher donor solution insulin concentration, shorter microneedles insertion time and fewer repeated insertions. The final scope of this work was to determine the effect of microneedle geometry and infusion protocols on microinfusion flow rate into skin in vitro. Infusion flow rates ranged from 21 to 1130 l/h was demonstrated using glass microneedles. The presence of a bevel at the microneedle tip, larger retraction distance and insertion depth, larger infusion pressure and the presence of hyaluronidase led to larger infusion flow rates.

Recently, there has been increased effort in researching methods for producing hollow nanostructures because of their potential impact in the fields of catalysis, separation processes, drug delivery, and energy storage and conversion devices. The purpose of this thesis is to describe a method for forming hollow inorganic-organic hybrid nanoboxes and nanoframes. This approach relies upon ionic liquid (1-butyl-3-methyl-imidazolium chloride) mediated auto-templating assembly of CaCO3 and chitosan to form nanoframes (two open faces) and nanoboxes (one open face). The average dimension of the nanostructures formed was 339 ± 95 x 299 ± 89 nm. Detailed structure of nanoboxes and nanoframes were obtained by 3-D electron tomography and X-ray diffraction. Chemical bonding was determined by FTIR, and the ratio of organics to inorganics in the nanostructures was determined by thermal gravimetric analysis. The chitosan to CaCO3 weigh ratio, mixing strength, temperature, and dialysis time were varied to further elucidate the method of formation. It was found that increasing the mixing power caused the equilibrium nanostructure dimension to decrease. On the other hand, varying the experimental temperature in the range of 80 to 160˚C did not affect the nanostructure dimension. The dialysis study showed that during dialysis the nanostructure core was increasingly removed. Nanoframes were observed after 72 hours of dialysis. With further dialysis, there was continued erosion of nanoframes. Results indicate that the concentration gradient and the solubility difference between the mixture components were responsible for this transformation.

Thesis (M.S.)--Ohio State University. / Bibliography: leaves 160-163. Available online via OhioLINK's ETD Center

Based on previous testing and analysis, it is believed that North American concrete design codes yield conservative shear designs for precast/prestressed hollow-core slabs in the 203 to 305 mm depth range. The objective of this research program is to calibrate the Canadian code shear equations to precast/prestressed hollow-core slabs, through testing a series of full-scale slabs to failure in shear. A total of twelve hollow-core slabs from one slab producer, using two types of extruders were tested in shear. Test variables include the bearing length and the prestressing level. Results are presented in terms of experimental to predicted capacity using the Canadian and American concrete design codes, the failure mode, crack profiles, and the critical section location for shear. It was concluded that the Canadian code shear equations are inappropriate for use with hollow-core slabs with low prestressing levels in the 203 to 305 mm depth range.

Based on previous testing and analysis, it is believed that North American concrete design codes yield conservative shear designs for precast/prestressed hollow-core slabs in the 203 to 305 mm depth range. The objective of this research program is to calibrate the Canadian code shear equations to precast/prestressed hollow-core slabs, through testing a series of full-scale slabs to failure in shear. A total of twelve hollow-core slabs from one slab producer, using two types of extruders were tested in shear. Test variables include the bearing length and the prestressing level. Results are presented in terms of experimental to predicted capacity using the Canadian and American concrete design codes, the failure mode, crack profiles, and the critical section location for shear. It was concluded that the Canadian code shear equations are inappropriate for use with hollow-core slabs with low prestressing levels in the 203 to 305 mm depth range.

Polymeric hollow fiber sorbents were functionalized with amine moieties for improving the carbon dioxide sorption capacity from flue gas to reduce the greenhouse gas emissions from coal-fired power plants. Three different experimental pathways were studied to form the amine-functionalized hollow fiber sorbents. Aminosilane functionalized cellulose acetate (CA) fibers, polyethyleneimine (PEI) functionalized polyamide-imide (PAI, Torlon® fibers and PEI post-infused and functionalized Torlon®-silica fibers were formed. CO₂ equilibrium sorption capacity data were collected by using the pressure decay sorption cell and thermal gravimetric analyzer. Other physio-chemical properties of the amine-functionalized fiber sorbents were characterized by using fourier-transform infrared spectroscopy, elemental analysis, and scanning electronic microscopy. Different reaction conditions were studied on the effect of sorption isotherms. Aminosilane-CA fibers were the first proof-of-concept for forming the amine functionalized polymer hollow fibers. PEI-PAI fibers were designed as a new method to reach enhanced sorption capacities than Aminosilane-functionalized CA fibers. PEI post-infused and functionalized Torlon®-silica fibers have further enhanced sorption capacity; however they easily degrade with similar reaction for forming PEI-PAI fibers. Lumen-side barrier layers were created successfully via post-treatment technique of using the crosslinked Neoprene® polymer onto PEI-functionalized PAI fibers. PEI-functionalized PAI fibers also have good cyclic stability and low heat of sorption.

Cancer is a disease with poor response rates on available treatments. Problems with resistance and intolerance against cancer drugs are major reasons for failure of the drugs. The need to discover new cancer drugs is important. In this thesis screening of new cancer drugs and evaluation of their mechanism of action are discussed. The aim of the thesis was to find new compounds active against neuroendocrine tumors (NETs). In paper I, we screened 1280 substances on two bronchial carcinoid cell lines and one pancreatic carcinoid cell line. Eleven of these compounds were found to have antitumor activity at low concentrations. The most active agents were brefeldin A, emetine, bortezomib and idarubicin, having IC50 values (the concentration of the drug where > 50% of the cells die) < 1μM. In addition, sanguinarine, Bay11-7085, mitoxantrone, doxorubicin, β-lapachone, NSC 95397 and CGP- 74514A were active with IC50 values < 10 μM.  In paper II, additional studies have been undertaken to investigate the combination effect of the most active drugs with conventional cytotoxic drugs used in clinical practice. If synergistic or additive effects are found, drugs with different mechanism of action and toxicity profiles may be combined, making it possible to reduce the toxic effects yet maintaining the antitumor activity. In paper III, studies were undertaken to find the mechanistic action, apoptosis or necrosis, of the drugs NSC 95397, brefeldin A, bortezomib and sanguinarine in NETs. All four drugs were shown to induce caspase-3 activity and nuclear fragmentation/condensation in the neuroendocrine tumor cell lines, indicating that their antitumor activity was induction of apoptosis. In paper IV, the mechanism of action was studied for CGP-74514A and emetine. Both drugs worked by induction of apoptosis. In addition, their cytotoxic activity was studied in a three-dimensional model, the in vitro hollow fiber model. The Hollow Fiber model permits more realistic simulation of in vivo drug effects in a controlled system providing data that more accurately reflects biological responses. Our results showed that the hollow fiber model may be suitable for studies of new drugs in the neuroendocrine tumor cell lines. / Title corrected from: Analyses of Dos-Response and Mechanistic Action of Different Anti-Cancer Drugs for Neuroendocrine Tumor Cell Lines

Ultrasonic techniques were used to detect hollow heart in potatoes nondestructively. Fifty Russet Burbank potatoes were evaluated physically and sonically. A pair of dry-coupling 50-kHz ultrasonic transducers were used to generate an ultrasonic pulse with a power level of 0.22 W for the test of acoustic transmission through whole potato tuber in a transverse direction at different locations along the longitudinal axis with a certain interval distance. It was found that the waveform analyses in time domain for a series of transmitted signals along the longitudinal axis of potato tuber, yielded the potential in detecting hollow heart in potatoes noninvasively. The transmission losses for potatoes having hollow heart were found to be greater than 0.28 dB/mm. This value was used as a criterion to indicate potatoes with hollow heart at an accuracy of 98 percent. The ability to detect hollow heart in potatoes was limited to a minimum cavity size of 0.5 cm3 because the interval distance between locations of measurement was relatively large compared to the size of the projected area of hollow heart. The accuracy of the detection would be improved if a smaller contact area for the transmitting transducer were used, and if the intervals between ultrasonic measurement locations were smaller. Physical properties of the tested potatoes were also recorded for consideration of their relationships with ultrasonic parameters. Physical properties of tested potatoes such as modulus of elasticity, tuber length, diameter, and weight, were found to have poor correlation with ultrasonic parameters such as ultrasonic velocity, attenuation coefficient, and root mean square voltage of transmitted signal. This study showed that if all potatoes with weights of 300 g or less were eliminated from a mass of incoming potatoes, only 80 percent of the total mass would have to be examined for hollow heart. / Master of Science

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