Cost leadership and pricing in conspicuous goods markets

We study competitive positioning and pricing strategies in markets with negative consumption externalities. Negative consumption externality is modeled as a decrease in preference for a product as more consumers purchase the same product. Using a two stage Hotelling type model, we show that a cost leader prices higher than the cost disadvantaged firm when the magnitude of negative consumption externality in the market is below a threshold otherwise the cost leader prices lower than the cost disadvantaged firm. Also, increase in population density decreases price differential between the cost leader and the cost disadvantaged firm.Negative Consumption Externalities, Cost Leadership, Conspicuous Goods, Pricing, Hotelling Models

Positioning and Pricing in a Variety Seeking Market

We study competitive positioning and pricing strategies in markets where consumers seek variety. Variety seeking behavior is modeled as a decrease in the willingness to pay for the product purchased on the previous purchase occasion. Using a three-stage Hotelling-type model, we show that the presence of variety seeking consumers reduces product differentiation offered in equilibrium, thereby explaining some otherwise counterintuitive findings in empirical research. We find that firms charge higher prices in Period 1 and lower prices in Period 2. The lower price in Period 2 represents the price incentive that firms need to offer to prevent the variety seeking consumers from switching. Furthermore, we find that the observed switching in a market may not fully capture the true magnitude of the underlying variety seeking tendencies among consumers. Finally, we show that the presence of variety seeking consumers leads to lower firm profits and a higher consumer surplus. Surplus increases for variety seeking consumers as well as regular consumers. Therefore, the presence of variety seeking consumers benefits everyone in the market

Differentiation, Niche and Cost Leadership Strategies: A Hotelling Based Analysis

Costs are an important determinant of prices charged by firms. The primary purpose of this paper is to study the impact of costs associated with differentiation and niche strategies on firm’s positioning and pricing decisions in a horizontally differentiated market. We analyze both sequential and simultaneous entry cases. In the sequential case, the cost of differentiation is an additional cost incurred by the second entrant and it depends on the degree of differentiation between itself and the first mover. The cost of following a niche strategy is a market level cost affecting both firms whereby firms incur a positive or negative cost if they want to make a niche product. Our analysis provide some surprising results, explains some conflicting empirical observations documented in previous research, and may also be useful for further empirical research in this area by providing sharper predictions about the impact of various types of costs on market outcomes. For example, we find that under some circumstances the cost disadvantaged firm can enjoy higher price-cost margins compared to the cost leader thereby suggesting that higher costs are a blessing in disguise. We also show analytically that a firm following differentiated or niche strategies charges a higher price than the cost leader if the cost of differentiated or niche strategy is sufficiently high and vice versa

Phosphonium polymethacrylates for siRNA delivery: effect of polymer and RNA structural parameters on polyplex assembly and gene knockdown

Synthetic polymers containing quaternary phosphonium salts are an emerging class of materials for the delivery of oligo/polynucleotides. In this work, cationic phosphonium salt-containing polymethacrylates –and their corresponding ammonium analogues– were synthesized by RAFT polymerization. Both the nature of the charged heteroatom (N vs. P) and the length of the spacer separating the cationic units along the polymer backbone (oxyethylene vs. trioxyethylene) were systematically varied. Polymers efficiently bound siRNA at N+/P- or P+/P- ratios of 2 and above. At a 20:1 ratio, small polyplexes (Rh: 4-15 nm) suitable for cellular uptake were formed that displayed low cytotoxicity. Whilst siRNA polyplexes from both ammonium and phosphonium polymers were efficiently internalised by GFP-expressing 3T3 cells, no knockdown of GFP expression was observed. However, 65% Survivin gene knockdown was observed when short interfering RNA (siRNA) was replaced with novel, multimerised long interfering liRNA (liRNA) in HeLa cells, demonstrating the importance of RNA macromolecular architecture on RNA-mediated gene silencing

Antimony-Doped Tin(II) Sulfide Thin Films

Thin-film solar cells made from earth-abundant, inexpensive, and nontoxic materials are needed to replace the current technologies whose widespread use is limited by their use of scarce, costly, and toxic elements. Tin monosulfide (SnS) is a promising candidate for making absorber layers in scalable, inexpensive, and nontoxic solar cells. SnS has always been observed to be a p-type semiconductor. Doping SnS to form an n-type semiconductor would permit the construction of solar cells with p-n homojunctions. This paper reports doping SnS films with antimony, a potential n-type dopant. Small amounts of antimony (1%) were found to greatly increase the electrical resistance of the SnS. The resulting intrinsic SnS(Sb) films could be used for the insulating layer in a p-i-n design for solar cells. Higher concentrations (5%) of antimony did not convert the SnS(Sb) to low-resistivity n-type conductivity, but instead the films retain such a high resistance that the conductivity type could not be determined. Extended X-ray absorption fine structure analysis reveals that the highly doped films contain precipitates of a secondary phase that has chemical bonds characteristic of metallic antimony, rather than the antimony–sulfur bonds found in films with lower concentrations of antimony.United States. Dept. of Energy. Sunshot Initiative (Contract DE-EE0005329)National Science Foundation (U.S.) (Grant CBET-1032955

Advanced Technologies for Oral Controlled Release: Cyclodextrins for oral controlled release

Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g. as osmotic pumps) and/ or hydrophobic CDs. New controlled delivery systems based on nanotechonology carriers (nanoparticles and conjugates) have also been reviewed

Optoelectronic characterization of CuInGa(S)2 thin films grown by spray pyrolysis for photovoltaic application

[EN] Copper-indium gallium disulfide (CIGS) is a good absorber for photovoltaic application. Thin films of CIGS were prepared by spray pyrolysis on glass substrates in the ambient atmosphere. The films were characterized by different techniques, such as structural, morphological, optical and electrical properties of CIGS films were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), spectrophotometer and Hall effect, respectively. After optimization, the deposited films structure, grain size, and crystallinity became more important with an increase of annealing time at 370 degrees C for 20 min. Transmission electron microscopy (TEM) analysis shows that the interface sheets are well crystallized and the inter planer distance are 0.25 nm, 0.28 nm, and 0.36 nm. The atomic force microscopy (AFM) observation shows that the grain size and roughness can be tolerated by optimizing the annealing time. The strong absorbance and low transmittance were observed for the prepared films with a suitable energy bandgap about 1.46 eV. The Hall effect measurement system examined that CIGS films exhibited optimal electrical properties, resistivity, carrier mobility, and carrier concentration which were determined to be 4.22 x 10(6) omega cm, 6.18 x 10(2) cm(2) V-1 S-1 and 4.22 x 10(6) cm(-3), respectively. The optoelectronic properties of CIGS material recommended being used for the photovoltaic application.Prof. Bouchaib HARTITI, The Senior Associate at ICTP, is very grateful to ICTP for permanent support. Prof. Mohamed Ebn Touhami, Director of the University Center for Analysis, Expertise, Transfer of Technology and Incubation, Kenitra, Morocco, is very grateful to CUA2TI for financial support. Thanks to Doctor Diogo M.F. Santos for the supervision of Amal Bouich's work during her research in CeFEMA research center. The authors also thank researchers from CeFEMA (IST-ULisboa, Portugal) and CUA2TI (FS-Kenitra Morocco) for their help.Bouich, A.; Hartiti, B.; Ullah, S.; Ullah, H.; Ebn Touhami, M.; Santos, DMF.; Marí, B. (2019). Optoelectronic characterization of CuInGa(S)2 thin films grown by spray pyrolysis for photovoltaic application. Applied Physics A. 125(8):1-9. https://doi.org/10.1007/s00339-019-2874-4S191258T. Feurer, P. Reinhard, E. Avancini, B. Bissig, J. Löckinger, P. Fuchs, S. Buecheler, Progress in thin film CIGS photovoltaics–Research and development, manufacturing, and applications. Prog. Photovolt. Res. Appl. 25(7), 645–667 (2017)A. Zegadi, M.A. Slifkin, M. Djamin, A.E. Hill, R.D. Tomlinson, A photoacoustic study of CuInxGa1− xSe2 alloys. Phys. Status Solidi (A) 133(2), 533–540 (1992)T.H. Sajeesh, A.R. Warrier, C.S. Kartha, K.P. Vijayakumar, Optimization of parameters of chemical spray pyrolysis technique to get n and p-type layers of SnS. Thin Solid Films 518(15), 4370–4374 (2010)J. Liu, D. Zhuang, H. Luan, M. Cao, M. Xie, X. Li, Preparation of Cu (In, Ga) Se2 thin film by sputtering from Cu (In, Ga) Se2 quaternary target. Progr. Nat. Sci. Mater. Int. 23(2), 133–138 (2013)M.I. Hossain, Fabrication and characterization of CIGS solar cells with In2 S3 buffer layer deposited by PVD technique. Chalcogenide Lett. 9(5), 185–191 (2012)M.A. Mughal, R. Engelken, R. Sharma, Progress in indium (III) sulfide (In2S3) buffer layer deposition techniques for CIS, CIGS, and CdTe-based thin film solar cells. Sol. Energy 120, 131–146 (2015)M. Powalla, M. Cemernjak, J. Eberhardt, F. Kessler, R. Kniese, H.D. Mohring, B. Dimmler, Large-area CIGS modules: Pilot line production and new developments. Sol. Energy Mater Sol. Cells 90(18–19), 3158–3164 (2006)M.E. Calixto, P.J. Sebastian, R.N. Bhattacharya, R. Noufi, Compositional and optoelectronic properties of CIS and CIGS thin films formed by electrodeposition. Sol. Energy Mater. Sol. Cells 59(1–2), 75–84 (1999)S. Jung, S. Ahn, J.H. Yun, J. Gwak, D. Kim, K. Yoon, Effects of Ga contents on properties of CIGS thin films and solar cells fabricated by co-evaporation technique. Curr. Appl. Phys. 10(4), 990–996 (2010)S. R. Ovshinsky, X. Deng, R. Young, U.S. Patent No. 5,231,047. Washington, DC: U.S. Patent and Trademark Office (1993).M. Kaelin, D. Rudmann, A.N. Tiwari, Low cost processing of CIGS thin film solar cells. Sol. Energy 77(6), 749–756 (2004)Fangdan Jiang, Jiayou Feng, Effect of temperature on selenization process of metallic Cu–In alloy precursors. Thin Solid Films 515(4), 1950–1955 (2006)S. Shirakata, Y. Kannaka, H. Hasegawa, T. Kariya, S. Isomura, Properties of Cu (In, Ga) Se2 thin films prepared by chemical spray pyrolysis. Jpn. J. Appl. Phys. 38(9R), 4997 (1999)Y.K. Kumar, G.S. Babu, P.U. Bhaskar, V.S. Raja, Effect of starting-solution pH on the growth of Cu2ZnSnS4 thin films deposited by spray pyrolysis. Phys. Status Solidi (A) 206(7), 1525–1530 (2009)M. Ajili, M. Castagné, N.K. Turki, Characteristics of CuIn1− xGaxS2 thin films synthesized by chemical spray pyrolysis. J. Lumin. 150, 1–7 (2014)B.J. Babu, S. Velumani, A. Kassiba, R. Asomoza, J.A. Chavez-Carvayar, J. Yi, Deposition and characterization of graded Cu (In1-xGax) Se2 thin films by spray pyrolysis. Mater. Chem. Phys. 162, 59–68 (2015)S.F. Varol, G. Babür, G. Çankaya, U. Kölemen, Synthesis of sol–gel derived nano-crystalline ZnO thin films as TCO window layer: effect of sol aging and boron. RSC Adv. 4(100), 56645–56653 (2014)J.A. Frantz, R.Y. Bekele, V.Q. Nguyen, J.S. Sanghera, A. Bruce, S.V. Frolov, I.D. Aggarwal, Cu (In, Ga) Se2 thin films and devices sputtered from a single target without additional selenization. Thin Solid Films 519(22), 7763–7765 (2011)C. Calderón, G. Gordillo, P. Bartolo-Pérez, F. Mesa, Effect of the deposition conditions on the optical, morphological and compositional properties of CuIn1− xGaxSe2 thin films prepared by a multistage process. Revista Mexicana de Física 53(7), 270–273 (2007)D. Schmid, M. Ruckh, F. Grunwald, H.W. Schock, Chalcopyrite/defect chalcopyrite heterojunctions on the basis of CuInSe2. J. Appl. Phys. 73(6), 2902–2909 (1993)U.C. Matur, S. Akyol, N. Baydoğan, H. Cimenoglu, The optical properties of CIGS thin films derived by sol-gel dip coating process at different withdrawal speed. Proc. Soc. Behav. Sci. 195, 1762–1767 (2015)A. Bouich, B. Hartiti, S. Ullah, M.E. Touhami, B. Mari, D.M.F. Santos, Investigation of the optical properties of CuIn (Se, S)2 thin films for photovoltaic application. Mater. Today Proc. 13, 663–669 (2019)K. Matsumura, T. Fujita, H. Itoh, D. Fujita, Characterization of carrier concentration in CIGS solar cells by scanning capacitance microscopy. Meas. Sci. Technol. 25(4), 044020 (2014)A. Bouich, B. Hartiti, S. Ullah, H. Ullah, M.E. Touhami, D.M.F. Santos, B. Mari, Experimental, theoretical, and numerical simulation of the performance of CuInxGa(1–x) S2 based solar cells. Optik 183, 137–147 (2019