scholarly journals Land degradation and sand dynamics in a steppe region (Nâama, south-western Algeria)

2017 ◽  
Vol 7 ◽  
Author(s):  
Grandi Mohamed ◽  
A. Hirche ◽  
Emilia Fernández-Ondoño ◽  
Francisco Martín-Peinado ◽  
M. Salamani ◽  
...  
Keyword(s):  
Land Degradation ◽  
Hierarchical Cluster ◽  
Major Elements ◽  
Mean Value ◽  
Environmental Implications ◽  
Environmental Threats ◽  
South Eastern ◽  
A Value ◽  
Western Algeria ◽  
Eastern Morocco

Land degradation is one of the most important environmental threats facing the international community. In North Africa, many semiarid and arid regions are suffering significant land degradation, which can be an impediment to sustainable development. Therefore; land degradation is monitored in a regional context for a better understanding of its causes and consequences. One of the main consequences is a notable increase in sand encroachment with negative environmental implications. For this reason, the dynamics of sands between south-eastern Morocco and the wilaya of Nâama, south-western Algeria, was studied. Sand samples gathered from six distinctive areas were subjected to physicochemical, colorimetric (redness index), morphoscopic (circularity), and geochemical analysis, and studied statistically using an analysis of variance (ANOVA), wind direction data, ternary plots and a hierarchical cluster of trace elements (K, Rb, Fe, Ti, Ca and Sr). In all areas, a clear dominance of the sand fraction appeared showing percentages ranging from 89 to 96%. Sampled areas were all carbonated, and the pH was alkaline, with close values ranging from 8.4 to 9. The mean circularity values ranged from 0.67 in Merzouga (Morocco) to 0.80 in El Aguer (Algeria). The lowest value of the redness index was noted in Merzouga with a mean value of 4. The Algerian areas showed an almost similar redness index with a value of 6 but the highest value was noted in Saadana with a value of 11. Geochemical approaches, based on ternary plots and dendrogram cluster indicating the abundance of major elements (Fe, Ca and K), were used as indicators of wind transport. Results suggested the existence of a Regional Wind Action System (RWAS) implicated in the transport of sand from south-eastern Morocco and its redistribution towards south-western Algeria. Merzouga was connected to all areas but particularly to nearby Saadana and Kasdir in the Algerian territory.

scholarly journals Characterization of different earthen construction materials in oasis of south-eastern Morocco (Errachidia Province)

2021 ◽  
Vol 14 ◽  
pp. e00496
Author(s):  
Abdellah Mellaikhafi ◽  
Amine Tilioua ◽  
Hanène Souli ◽  
Mohammed Garoum ◽  
Moulay Ahmed Alaoui Hamdi
Keyword(s):  
Construction Materials ◽  
South Eastern ◽  
Earthen Construction ◽  
Eastern Morocco

PEMANFAATAN LIMBAH KOTORAN SAPI SEBAGAI PENGGANTI SEBAGIAN SEMEN DALAM PEMBUATAN BATAKO

2020 ◽  
Vol 15 (2) ◽  
pp. 53-57
Author(s):  
Kiki Kurniawan ◽  
Prihantono Prihantono ◽  
Rosmawita Saleh
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Mean Value ◽  
Cow Dung ◽  
A Value ◽  
Average Water ◽  
Hollow Brick ◽  
Average Compressive Strength

The results showed the use of cow dung waste can increase the compressive strength of hollow brick from any composition of waste. Hollow brick with cow dung substitution of 0% has an average compressive strength value 44.75 Kg/Cm2 has an average water absorption of 14.31%, hollow brick with cow dung substitution of 5% has a value of compressive strength average 47.47 Kg/Cm2 has an average water absorption of 15.67%, Batako perforation with cow dung substitution of 7.5% has an average compressive strength value of 51.83 Kg/Cm2 has the absorption water averaging 13.71%, batako perforated with substitution of cow dung waste of 10% has an average compressive strength value 53.81 Kg/Cm2 has an average water absorption of 10.04%, hollow brick with substitution cow dung waste of 12.5% has an average compressive strength value of 50.66 Kg/Cm2 has an average water absorption of 23.6%, hollow brick with cow dung substitution of 15% average 48.84 Kg/Cm2 has an average water absorption of 19.72%. The optimum compressive strength value was obtained from percentage substitution of cow dung waste at 10% with mean value of compressive strength 53,81 Kg/Cm2 with average water absorption 10,04%.

scholarly journals Hydrological prediction in a non-stationary world

2007 ◽  
Vol 11 (1) ◽  
pp. 408-414 ◽  
Author(s):  
R. T. Clarke
Keyword(s):  
Time Series ◽  
Urban Development ◽  
Mean Value ◽  
South American ◽  
Drainage Basins ◽  
South Eastern ◽  
Rapid Changes ◽  
Hydrological Prediction ◽  
Random Fluctuations ◽  
Linear Trends

Abstract. The paper discusses evidence that common assumptions in the analysis of hydrological time series (homogeneous variability in random fluctuations about a constant mean value) may not be appropriate for some South American drainage basins. Relatively rapid changes have occurred, and are occurring, as a consequence of replacing mature forest by short crops and urban development. Some research claims to have detected non-linear trends in streamflow in rivers draining the south-eastern part of the sub-continent, together with decadal fluctuations and interannual peaks at ENSO timescales. The paper discusses the implications of such changes for hydrological practices now in widespread and largely unquestioned use.

scholarly journals Analysis of the coefficient of variation in shear and tensile bond strength tests

2005 ◽  
Vol 13 (3) ◽  
pp. 243-246 ◽  
Author(s):  
Fábio Lourenço Romano ◽  
Gláucia Maria Bovi Ambrosano ◽  
Maria Beatriz Borges de Araújo Magnani ◽  
Darcy Flávio Nouer
Keyword(s):  
Coefficient Of Variation ◽  
Mean Value ◽  
Scientific Article ◽  
A Value ◽  
Statistical Analysis System ◽  
Strength Tests ◽  
Analysis System ◽  
Very High

The coefficient of variation is a dispersion measurement that does not depend on the unit scales, thus allowing the comparison of experimental results involving different variables. Its calculation is crucial for the adhesive experiments performed in laboratories because both precision and reliability can be verified. The aim of this study was to evaluate and to suggest a classification of the coefficient variation (CV) for in vitro experiments on shear and tensile strengths. The experiments were performed in laboratory by fifty international and national studies on adhesion materials. Statistical data allowing the estimation of the coefficient of variation was gathered from each scientific article since none of them had such a measurement previously calculated. Excel worksheet was used for organizing the data while the sample normality was tested by using Shapiro Wilk tests (alpha = 0.05) and the Statistical Analysis System software (SAS). A mean value of 6.11 (SD = 1.83) for the coefficient of variation was found by the data analysis and the data had a normal distribution (p>0.05). A range classification was proposed for the coefficient of variation from such data, that is, it should be considered low for a value lesser than 2.44; intermediate for a value between 2.44 and 7.94, high for a value between 7.94 and 9.78, and finally, very high for a value greater than 9.78. Such classification can be used as a guide for experiments on adhesion materials, thus making the planning easier as well as revealing precision and validity concerning the data.

A new Plattenkalk Konservat Lagerstätte in the Upper Cretaceous of Gara Sbaa, south-eastern Morocco

2011 ◽  
Vol 32 (4) ◽  
pp. 433-446 ◽  
Author(s):  
David M. Martill ◽  
Nizar Ibrahim ◽  
Paulo M. Brito ◽  
Lahssen Baider ◽  
Samir Zhouri ◽  
...  
Keyword(s):  
Upper Cretaceous ◽  
South Eastern ◽  
Eastern Morocco

Music, Borders and Nationhood in Algeria

Algeria ◽  
2017 ◽  
Author(s):  
Tony Langlois
Keyword(s):  
Music Industry ◽  
Regional Identity ◽  
Local Form ◽  
Pop Music ◽  
The Core ◽  
Musical Practices ◽  
Western Algeria ◽  
Eastern Morocco ◽  
Musical Genres

This chapter looks at the role of musical genres in the borderland between Oran in Western Algeria and Oujda in Eastern Morocco – in many ways a single cultural and economic zone that is distinct from the core of each of their respective nations. Once this had been the boundary of the Ottoman Empire, but at other times a refuge for political dissidents from either side in their many anti-colonial struggles. Today the cities are economically linked by smuggling and culturally by language, common tradition and strong musical connections – the raï pop music industry is strong on both sides of the border, but as important is the local form of ‘classical’ Andalous music tarab el gharnati and Berber ‘folk’ genres. Music itself marks boundaries of taste, heritage and allegiance, and these often have a tangential relationship to those demarcated by nationalist discourses. The chapter considers the ways in which musical practices preserve a sense of regional identity and allegiance despite the formal closure of the border in 1994. It looks at the economic and cultural consequences of this relationship and at the efforts of the Algerian government to maintain formal boundaries and address the broader context of cross-border cultural flow, not only with Morocco, but, increasingly, the wider mediated world.

Fertility investigations on the black earth wheatlands of the Darling Downs, Queensland. III. Mineral nitrogen in the soil and its relation to the wheat crop

1960 ◽  
Vol 11 (1) ◽  
pp. 27 ◽  
Author(s):  
SA Waring ◽  
LJH Teakle
Keyword(s):  
Grain Yield ◽  
Ammonia Nitrogen ◽  
Mean Value ◽  
Mineral Nitrogen ◽  
Wheat Crop ◽  
Nitrogen Accumulation ◽  
A Value ◽  
The Mean ◽  
The One ◽  
Growing Crop

The level of mineral nitrogen in the soil under fallow and crop was measured for the years 1951 to 1953. Relationships of mineral nitrogen at planting to yield and nitrogen content of wheat grain and straw were examined. Values for nitrate nitrogen at the end of the fallow period ranged most commonly from 10 to 20 µg/g in the surface 2 ft and from 0 to 10 µg/g at 2-4 ft. Approximately one-third of the sites showed an increase from the third to the fourth foot. One site showed extremely high values throughout the profile, particularly at 3-4 ft where a value of 127 µg/g was recorded. Values for ammonia nitrogen were most commonly in the range of 0-3 µg/g . Under the growing crop, mineral nitrogen declined for most depths in the period from planting up to September or October, after which there was little further change to harvest. Uptake of mineral nitrogen was normally greatest from the surface 2 ft of soil. Below 3 ft there were two groups of sites. One group showed moderate to high uptake and the second group low uptake. The low uptake in the latter group provides a reason for mineral nitrogen accumulation below 3 ft at some sites. Mineral nitrogen to 4 ft at planting averaged 126 lb/ac, excluding the one site with exceptionally high values. This was double the mean value of 63 lb/ac for nitrogen recovered in grain and straw, for crops planted in May-June. These figures, combined with trends in the soil under crop, suggest that most of the nitrogen used by the crop was derived from that in the soil at planting. Correlations between mineral nitrogen at planting and grain yield were mostly non-significant, suggesting that in general nitrogen was not an important factor limiting yield. Low grain yield and protein percentage were recorded at a number of sites which had been cultivated more than 50 years.

Identifying ecosystem service hotspots for targeting land degradation neutrality investments in south-eastern Africa

2018 ◽  
Vol 159 ◽  
pp. 75-86 ◽  
Author(s):  
Louise Willemen ◽  
Neville D. Crossman ◽  
Simone Quatrini ◽  
Benis Egoh ◽  
Felix K. Kalaba ◽  
...  
Keyword(s):  
Land Degradation ◽  
Ecosystem Service ◽  
Eastern Africa ◽  
South Eastern
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