diff --git a/exploratory_analysis.ipynb b/exploratory_analysis.ipynb
index 0966b8a3cbc96b29fadc0cbf62bafb21f5029393..b4f07dc860840c037dfdfd125c38a6d4a5a0e1ee 100644
--- a/exploratory_analysis.ipynb
+++ b/exploratory_analysis.ipynb
@@ -78,8 +78,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:23.999902Z",
-     "start_time": "2021-01-05T14:25:23.354783Z"
+     "end_time": "2022-01-28T12:24:04.045301Z",
+     "start_time": "2022-01-28T12:24:03.255791Z"
     }
    },
    "outputs": [],
@@ -120,8 +120,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:24.088808Z",
-     "start_time": "2021-01-05T14:25:24.001958Z"
+     "end_time": "2022-01-28T12:24:04.132035Z",
+     "start_time": "2022-01-28T12:24:04.046837Z"
     },
     "scrolled": true
    },
@@ -180,8 +180,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:24.095166Z",
-     "start_time": "2021-01-05T14:25:24.090901Z"
+     "end_time": "2022-01-28T12:24:04.136983Z",
+     "start_time": "2022-01-28T12:24:04.133584Z"
     }
    },
    "outputs": [],
@@ -201,8 +201,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:24.107786Z",
-     "start_time": "2021-01-05T14:25:24.096821Z"
+     "end_time": "2022-01-28T12:24:04.148465Z",
+     "start_time": "2022-01-28T12:24:04.138581Z"
     }
    },
    "outputs": [],
@@ -279,8 +279,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:24.121703Z",
-     "start_time": "2021-01-05T14:25:24.109367Z"
+     "end_time": "2022-01-28T12:24:04.163979Z",
+     "start_time": "2022-01-28T12:24:04.149877Z"
     }
    },
    "outputs": [],
@@ -380,8 +380,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:24.141593Z",
-     "start_time": "2021-01-05T14:25:24.122900Z"
+     "end_time": "2022-01-28T12:24:04.169525Z",
+     "start_time": "2022-01-28T12:24:04.165297Z"
     }
    },
    "outputs": [],
@@ -417,8 +417,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:24.157453Z",
-     "start_time": "2021-01-05T14:25:24.142956Z"
+     "end_time": "2022-01-28T12:24:04.178213Z",
+     "start_time": "2022-01-28T12:24:04.170908Z"
     },
     "scrolled": true
    },
@@ -439,8 +439,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:25.703372Z",
-     "start_time": "2021-01-05T14:25:24.159666Z"
+     "end_time": "2022-01-28T12:24:05.954615Z",
+     "start_time": "2022-01-28T12:24:04.180204Z"
     },
     "scrolled": false
    },
@@ -476,8 +476,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:25.726629Z",
-     "start_time": "2021-01-05T14:25:25.705254Z"
+     "end_time": "2022-01-28T12:24:05.989546Z",
+     "start_time": "2022-01-28T12:24:05.956318Z"
     },
     "scrolled": true
    },
@@ -493,8 +493,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:25.731276Z",
-     "start_time": "2021-01-05T14:25:25.728009Z"
+     "end_time": "2022-01-28T12:24:05.994152Z",
+     "start_time": "2022-01-28T12:24:05.990892Z"
     }
    },
    "outputs": [],
@@ -518,8 +518,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:25.966762Z",
-     "start_time": "2021-01-05T14:25:25.732453Z"
+     "end_time": "2022-01-28T12:24:06.247420Z",
+     "start_time": "2022-01-28T12:24:05.995531Z"
     },
     "scrolled": false
    },
@@ -549,14 +549,14 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:25.975637Z",
-     "start_time": "2021-01-05T14:25:25.968619Z"
+     "end_time": "2022-01-28T12:24:06.253402Z",
+     "start_time": "2022-01-28T12:24:06.248640Z"
     }
    },
    "outputs": [],
    "source": [
     "def composition_RS_ZB (df):\n",
-    "    df_cm = pd.DataFrame (columns=['RS','ZB','Materials in cluster'])\n",
+    "    df_cm = pd.DataFrame (columns=['RS','ZB','Materials in cluster'], dtype=object)\n",
     "\n",
     "    n_clusters = df['cluster_label'].max() + 1\n",
     "  \n",
@@ -576,8 +576,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.013983Z",
-     "start_time": "2021-01-05T14:25:25.977220Z"
+     "end_time": "2022-01-28T12:24:06.272942Z",
+     "start_time": "2022-01-28T12:24:06.254593Z"
     },
     "scrolled": true
    },
@@ -616,8 +616,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.028804Z",
-     "start_time": "2021-01-05T14:25:26.015145Z"
+     "end_time": "2022-01-28T12:24:06.280755Z",
+     "start_time": "2022-01-28T12:24:06.274223Z"
     },
     "scrolled": true
    },
@@ -632,8 +632,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.099022Z",
-     "start_time": "2021-01-05T14:25:26.029990Z"
+     "end_time": "2022-01-28T12:24:06.350477Z",
+     "start_time": "2022-01-28T12:24:06.281949Z"
     },
     "scrolled": false
    },
@@ -647,8 +647,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.127167Z",
-     "start_time": "2021-01-05T14:25:26.100850Z"
+     "end_time": "2022-01-28T12:24:06.368164Z",
+     "start_time": "2022-01-28T12:24:06.351821Z"
     },
     "scrolled": true
    },
@@ -671,8 +671,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.283016Z",
-     "start_time": "2021-01-05T14:25:26.128369Z"
+     "end_time": "2022-01-28T12:24:06.539544Z",
+     "start_time": "2022-01-28T12:24:06.369442Z"
     }
    },
    "outputs": [],
@@ -710,8 +710,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.291099Z",
-     "start_time": "2021-01-05T14:25:26.284621Z"
+     "end_time": "2022-01-28T12:24:06.545860Z",
+     "start_time": "2022-01-28T12:24:06.540913Z"
     }
    },
    "outputs": [],
@@ -726,8 +726,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.372635Z",
-     "start_time": "2021-01-05T14:25:26.292763Z"
+     "end_time": "2022-01-28T12:24:06.625305Z",
+     "start_time": "2022-01-28T12:24:06.547088Z"
     },
     "scrolled": false
    },
@@ -741,8 +741,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.401536Z",
-     "start_time": "2021-01-05T14:25:26.374424Z"
+     "end_time": "2022-01-28T12:24:06.643453Z",
+     "start_time": "2022-01-28T12:24:06.626986Z"
     }
    },
    "outputs": [],
@@ -791,8 +791,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-11T15:53:04.983731Z",
-     "start_time": "2021-01-11T15:53:04.974426Z"
+     "end_time": "2022-01-28T12:24:06.660245Z",
+     "start_time": "2022-01-28T12:24:06.644775Z"
     }
    },
    "outputs": [],
@@ -816,8 +816,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.422572Z",
-     "start_time": "2021-01-05T14:25:26.403215Z"
+     "end_time": "2022-01-28T12:24:06.682247Z",
+     "start_time": "2022-01-28T12:24:06.661653Z"
     }
    },
    "outputs": [],
@@ -832,8 +832,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.499772Z",
-     "start_time": "2021-01-05T14:25:26.423842Z"
+     "end_time": "2022-01-28T12:24:06.778337Z",
+     "start_time": "2022-01-28T12:24:06.684389Z"
     }
    },
    "outputs": [],
@@ -846,8 +846,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.531074Z",
-     "start_time": "2021-01-05T14:25:26.503236Z"
+     "end_time": "2022-01-28T12:24:06.801127Z",
+     "start_time": "2022-01-28T12:24:06.780317Z"
     }
    },
    "outputs": [],
@@ -893,8 +893,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-11T15:53:05.117794Z",
-     "start_time": "2021-01-11T15:53:05.101544Z"
+     "end_time": "2022-01-28T12:24:06.815324Z",
+     "start_time": "2022-01-28T12:24:06.802508Z"
     }
    },
    "outputs": [],
@@ -914,8 +914,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.669427Z",
-     "start_time": "2021-01-05T14:25:26.533056Z"
+     "end_time": "2022-01-28T12:24:06.988380Z",
+     "start_time": "2022-01-28T12:24:06.816753Z"
     }
    },
    "outputs": [],
@@ -939,8 +939,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.798561Z",
-     "start_time": "2021-01-05T14:25:26.671018Z"
+     "end_time": "2022-01-28T12:24:07.112300Z",
+     "start_time": "2022-01-28T12:24:06.989816Z"
     }
    },
    "outputs": [],
@@ -953,8 +953,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.865309Z",
-     "start_time": "2021-01-05T14:25:26.800153Z"
+     "end_time": "2022-01-28T12:24:07.176493Z",
+     "start_time": "2022-01-28T12:24:07.113688Z"
     },
     "scrolled": false
    },
@@ -968,8 +968,8 @@
    "execution_count": null,
    "metadata": {
     "ExecuteTime": {
-     "end_time": "2021-01-05T14:25:26.897739Z",
-     "start_time": "2021-01-05T14:25:26.866609Z"
+     "end_time": "2022-01-28T12:24:07.208455Z",
+     "start_time": "2022-01-28T12:24:07.178734Z"
     }
    },
    "outputs": [],
@@ -1012,7 +1012,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.8.8"
+   "version": "3.7.3"
   }
  },
  "nbformat": 4,