The population of spider feeding on insect pests of cotton was observed throughout the growth period of the crop, being maximum in the month of July. Chrysoperla was observed from second fortnight of June to harvesting of the crop being maximum in November. The incidence of coccinellids was recorded from the middle of August to middle of September and remained till harvesting of the crop being maximum in the first fortnight of November. A positive significant effect of maximum and minimum temperature on spider and negative significant effect on population of chrysoperla and coccinellids was recorded. Evening RH exerted positive significant effect on spider and negative significant effect on coccinellids.
The theoretical estimation of sound absorption coefficient of a surface may give very different results. This will depend on the type of sound field assumed in the theoretical model used for the estimation of its sound absorption coefficient. Absorption coefficients for normal and diffuse sound fields are widely known, although they may be far from the absorption values given by an absorbing material when it is finally installed inside a room or enclosed space, where a sound field closer to a spherical wavefront is more likely to be found. This work presents a theoretical study, which is addressed at obtaining a mathematical expression to calculate the sound absorption coefficient for a variable range of incidence angles, called αs. The presented method uses a circular sound field incidence as an approximation to a spherical incidence. The estimation of this coefficient αs is based on obtaining the incident and reflected sound fields for a surface located facing a lineal source. The advantage of this calculation method over others lies on its capability to give results for circular, normal and random wave incidence depending on the range of incidence angles considered in the calculation.
At the end of August 2012 the Polish Parliament enacted the Act on State Marine Accident Investigation Commission, which regulates its organization and operation. The Act transposed, within its regulation, Directive 2009/18/EC of the European Parliament and of the Council of 23 April 2009 establishing the fundamental principles governing the investigation of accidents in the maritime transport sector and is based on the Code of the International Standards and Recommended Practices for a Safety Investigation into a Marine Casualty or Marine Incident (Casualty Investigation Code), issued by the International Maritime Organization (IMO) together with amendments to the SOLAS Convention. The purpose of the Directive, as well as the Casualty Investigation Code, is to improve maritime safety and the prevention of pollution by ships by facilitating the expeditious holding of safety investigations and proper analysis of marine casualties and incidents in order to determine their causes. The EU Parliament obliged, through the Directive, the EU Member States to ensure that the safety investigations are conducted under the responsibility of an impartial permanent investigative body, endowed with the necessary powers, and by suitably qualified investigators, competent in matters relating to marine casualties and incidents. This impartial permanent investigative body had been named in Poland: Państwowa Komisja Badania Wypadków Morskich [the State Marine accident Investigation Commission] and began its operation in May 2013 upon the appointment, by the Minister of Transport, Construction and Maritime Economy, of the third one of five statutory members of the Commission. Since the beginning of its activity the Commission has initiated 77 safety investigations, prepared and adopted 272 resolutions, published 53 safety reports and issued more than 30 safety recommendations. The establishment and activity of the Commission leads to greater awareness of casualty causation and has a positive impact on the level of maritime safety.
This paper presents an approximate analytical model for estimating the transmission loss (TL) of a finite rectangular plate in the low frequency range, which is based on the modal summation approach (MSA) taking into account the modal radiation impedance and fluid loading. The mode-dependent radiation resistance is calculated using the Rayleigh integral. The fluid loading is taken into account through the natural frequency modified by the added mass. The results are compared with the ones of Statistical Energy Analysis (SEA) coupled with FEM and FEM coupled with BEM. In addition, the effects of the various vibration modes and the fluid loading on TL, and a way for reducing the calculation time are discussed.
This article surveys the relations between the Polish Radio and the German Broadcasting Corporation (Reichs-Rundfunk-Gesellschaft) in the interwar period. In its early phase the relationship was overshadowed by disputes over programmes on Upper Silesia and the takeover by a German company of the radio station in the Free City of Gdańsk (Danzig). After Hitler became chancellor in 1933 there was a marked improve- ment in relations: the two parties even made an agreement to relay each other's programmes. However, in September 1939 the German radio network (RRG) actively aided the German army in its invasion of Poland.