Abstract: A three-sided, rectilinear bridge or culvert structure comprises a pair of vertical sidewalls set in preformed or cast in place footers or existing supports and an integral, planar, horizontal span. The footers preferably include a sidewall receiving channel on their upper surfaces. There is no lower or bottom portion of the structure such as is found in conventional box culverts and thus, that region between the footers and sidewalls is open and readily permits water flow through the structure in its natural watercourse, lessening the likelihood of debris collection within the structure. The structure is cast concrete reinforced with conventional reinforcing bar or welded wire mesh. A wide range of rise/span (height/width) proportions may be accommodated in structures having spans up to about thirty feet.

Abstract: A laminating machine for laminating outer sheets one on each side of an inner sheet, in which all three sheets are moved along in alignment, one spaced above the other, with their edges enclosed by adjustable side covers. The side covers together with the top and bottom sheets form a chamber. Contact adhesive is sprayed on the sheets at the entrance to the chamber. Heater bars span the chamber near the entrance to dry the adhesive. A suction box at the other end of the chamber draws air through the entrance, over the adhesive and heater bars, and then exhausts the solvent laden air. Beyond the suction box, pinch rollers compress the three sheets together to laminate them.

Abstract: The long-term variation of bending moment distribution caused by creep in a continuous beam errected sequentially in span-length sections with overhangs is analyzed. A linear aging creep law is assumed. The problem involves changes of the structural system from statically determinate to indeterminate, a gradual increase in the number of redundant moments, and age differences between various cross sections. A system of Volterra integral equations for the history of support bending moments is derived. By considering infinately many equal spans, which is good enough whenever there are many spans, one can take advantage of a periodicity condition for the construction cycle; this reduces the problem to a single equation which is of a novel type in creep theory—an integral-difference equation involving time lags in the integrated unknown. The solution exhibits sudden jumps at times equal to multiples of the construction cycle. The jumps decay with time roughly in a geometric progression. Approximation of time integrals with finite sums yields a large system of simultaneous linear algebraic equations. These equations cannot be solved recurrently, step-by-step. By solving the large equation system with a computer, the effects of the duration of the construction cycle, of concrete age at assembly of span from segments and of the overhang length are studied numerically.

Abstract: In a PCM telecommunications switching system, an arrangement for deriving a clock signal from incoming PCM data of a digital span is shown. This derived clock signal is synchronized and continuously locked to the incoming PCM data of the digital span. The present digital phase locking arrangement cyclically adjusts the derive clock signal so that on the average synchronism is maintained.

Abstract: A building (1) comprising walls (2-6) consisting of frameworks (12) of horizontal (9) and vertical (8) posts provided at least on one side with plates (10, 11) ensuring resistance to deformation and span elements disposed on said walls such as floor beams (19) or rafters (93). Each wall is composed of separate sections (7) having at least one circumferential framework (12) of cold-rolled steel plate profiles, adjacent sections being mounted to one another by their vertical peripheral posts (8) and the span elements (19) being disposed above the vertical peripheral posts (8).

Abstract: The multiple Fourier technique is used to compare the stress fields in single span deep beams due to uniform loading at the top edge and at the bottom edge. The method involves the superposition of three stress functions. The first stress function is used to satisfy the boundary conditions on the upper and lower edges of the beam. The second and third stress functions are used to satisfy the boundary conditions on the vertical edges of the beam. This approach allows to satisfy all the required boundary conditions. Contour maps of the stress field reveal the existence of regions of pure tension and pure compression. These regions indicate proneness to spalling, bursting or crushing.

Abstract: In a telecommunications switching system, a thick film digital span transmission circuit is connected between a digital span and a switching network of the switching system. The circuit converts unipolar switching network data to bipolar data for digital span use. The present circuit is relatively small in size and has minimal power consumption. This circuit also provides for attenuating and shaping the pulses transmitted to the digital span.

Abstract: Greenhouses should be designed to meet requirements of construction costs, durability against loads and the possibility of providing suitable environment to plant growth. To get guides to design an optimal greenhouse from the above-mentioned three viewpoints, one of the optimization techniques, which is called the steepest descent method, is applied in this study. The direct light transmission into the greenhouse in winter is regarded as one of the most important environmental factors.The steepest descent method gives the combination of the design variables which constitute the optimal (minimum or maximum) value in the objective function under some constraints. In this study the design variables were, for example, the shape of the house, the moment of inertia and crosssection features of each member and the ratch measure. The allowable stress or deflection of each member played a role of constraints in the course of the optimization. The objective function was the construction cost or the direct light transmission. In the steepest descent method, however, only one objective function is allowed. For this reason the following two steps were used. First the construction cost (Js) is chosen as the objective function and is minimized. Then the inequality (1) is added to the constraints and the light transmission is maximized, where k is the coefficient of construction cost allowance and larger than 1.0, and Jsopt is the minimum construction cost.Because in the steepest descent method all variables should be continuous and differentiable, some discontinuous variables, e.g. the number of purlins, were approximated with appropriate continuous functions. For the same reason any size and shape of steel member were assumed to exist. The crosssection features of the member are expressed with three independent variables on the basis of the empirical relations.The optimizations were carried out under the conditions of a snow load of 30cm and a wind speed of 50m/s. The span was fixed at 9m. The latitude and the coefficient of construction cost allowance in the optimization of the light transmission were 34°N and 1.10, respectively. The following points became clear by the optimizations.1) The steepest descent method can be applied to greenhouse design and the results show appreciable improvement both in the construction cost and in the light transmission in comparison with an example of commercial greenhouses.2) The results of the optimization of the construction cost (cost optimization, hereafter) and the light transmission of the N-S oriented greenhouse (N-S optimization, hereafter) show a symmetric shape, whereas the optimal E-W oriented greenhouse has a ridge nearer to the south wall, so that the south roof slope becomes steeper.3) Every optimization results in a ratch measuer of about 4m, which is wider than that of commercial greenhouses.4) The moment of inertia of the rafters and the posts ranges from 150 to 290cm4. In the cases of the cost and N-S optimizations, the rafters have a larger moment of inertia than the posts. In the E-W optimization, the north rafter has an appreciably larger moment of inertia than the three others.5) The cost optimization shows that members of the crosssection with larger depth and width are more suitable for the rafters and the posts, if the moment of inertia is the same. This holds true for the north members in the E-W optimization and for the posts in the N-S optimization. In the E-W oriented greenhouse, a member with shorter depth and larger section area and a member with shorter width are more suitable for the south rafter and for the south post, respectively.6) In this study the strength of the glass was not taken into consideration. This resulted in very wide purlin intervals, which seem to be unrealistic, but this still proves that larger purlins with wider intervals are more suitable

Abstract: This research focused on developing a pre-processor (data generator) and a post-processor for an existing computer program, SLAB49, for the analysis of integral grid-beam systems. The pre- and post-processors were specialized for four widely used bridge classes: (1) steel beam and slab section, (2) prestressed girder and slab section, (3) slab section with or without integral curbs, and (4) simple span pan-formed sections. Regularly skewed bridges may also be considered. The pre-processor takes simplified inputs with regard to bridge type, geometry, and loading and provides automatically the more detailed information required by the parent program SLAB49. The post-processor searches through the results from SLAB49 and provides a more convenient arrangement for output thereby expediting the interpretation of the results of the analysis. The pre-processor accesses data bases containing bridge class information and overload configurations. A computer program was developed which allows for the data bases to be updated for future implementation as needed. (FHWA)

Abstract: PURPOSE:To make a span adjustment without using precise parts by providing an integration period adjusting means for adjusting an integration period and varying the length of the integration period. CONSTITUTION:The output of a transducer 1 is supplied to and amplified by an amplifier 2 at a specific amplification factor and the resulting signal is supplied to an A/D converting circuit 3. Span data set in a span setter 4, on the other hand, is supplied to a control circuit 5 as the integration period adjusting means. The control circuit 5 controls the A/D converting circuit 3 to vary the length of the integration period. Consequently, the integration period of A/D converting operation is adjusted to adjust the span. Thus, the span adjustment is made without using precise parts such as a precise resistance, precise capacitor, etc.

Abstract: The purpose of the investigation presented herein is to study the behavior of proposed nonprismatic folded plates. The laboratory test program consisted of tests on two sand‐araldite models of variable depth folded plates of a single unit of inverted trough section each with a 1 m span. The proposed nonprismatic shape is obtained by varying the depth of the folded plate parabolically along the span with maximum depth at mid span. The ratios of mid span depth to the depth at support for the two models were 2 and 4. The experiment was conducted for three loading conditions: (1) Uniformly distributed load on top plate and line load along both valleys; (2) uniformly distributed load on top plate; and (3) uniformly distributed load on top plate and line load along one of the valleys. The deflections, longitudinal stresses, and transverse moments predicted by the force method of analysis are compared with those obtained from the experiment and are found to be in good agreement.

Abstract: PURPOSE:To measure the spans between rails and girders for a crane automatically and continuously by detecting the distance to the rails through distance detectors which are fitted to the crane opposite to the flanks of the rails. CONSTITUTION:The crane 1 is run and distance detectors 6 and 6', and 7 and 7' for the rails and girders fitted to the crane 1 detect the distances to the rails 3 and 3', and girders 4 and 4'. Their detection signals are sent to the computing element 8 in an operation room 5, and the spans between the rails 3 and 3', and girders 4 and 4' are calculated and recorded on a recorder 9.

Abstract: Tremendous progress has been made in the art and construction of long span bridges, of which history goes back almost to the third millennium B.C. In this evolution structural concepts and strengths of materials used have played key roles. The limiting span is defined as that span at which the structural system will just support itself. The ultimate span is the maximum span possible for a particular type of construction. Comparison is made between ultimate spans and those already built to indicate that in concrete construction the limit has almost been reached but for steel construction much larger spans are possible.

Abstract: A system for measuring and controlling fluid comprises ultra-sonic signal transmission means (16), echo signal receiving means (16), and means (53) for measuring the time span between the transmission of the ultra-sonic signal and a receipt of the echo signal to obtain the distance that the signal has travelled. The system may include means responsive to said distance being outside of a certain span for varying the distance so as to bring the distance to a desired value within the span. The system may measure liquid level or flow rate when the ultra-sonic signal is reflected from a drag body (Fig. 3, not shown).